Papers for

ai safety engineers

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

Agentic AI jailbreaking faces new challenges despite stronger safety measures

SoK: Rethinking Jailbreaking in the Era of Agentic AI: Attacks, Defenses, and Practical Consideration

Abstract: Large language models (LLMs) are rapidly evolving from conversational assistants into agentic AI systems that reason, plan, invoke tools, maintain persistent memory, communicate with other agents, and execute multi-step tasks. At the same time, modern models exhibit substantially stronger native safety alignment than earlier generations on which many jailbreak attacks and defenses were originally studied. This shift raises a fundamental question: \textit{which established jailbreak-security findings remain valid in the era of modern LLMs and agentic AI?} We address this question through a Systematization of Knowledge (SoK) that reframes jailbreak security around the full agentic execution pipeline. We develop unified taxonomies of attacks and defenses spanning user interaction, planning and reasoning, memory, tool use, and inter-agent communication, and introduce a security--utility--efficiency evaluation framework that separates native harmful-prompt safety, adversarial jailbreak robustness, and agent-level security outcomes. We further conduct a controlled empirical study of representative attacks and defenses within a common agentic framework. Our results reveal three important gaps. First, strong native alignment does not imply robustness to adversarial jailbreaks. Second, defense effectiveness is highly model-, attack-, and component-dependent and can come at substantial cost in over-refusal, utility, and latency. Third, low final-response attack success can mask severe intermediate compromise: planning, memory, and tool interactions may remain unsafe even when the final response is successfully filtered. These findings motivate a shift from response-centric jailbreak defense toward cross-layer, execution-aware security that protects agent state, component transitions, and external actions while preserving practical utility and efficiency.

Fri 11 SeptArtificial Intelligence
The gist
Large language models are evolving into smart agents that can plan and use tools, but this creates new challenges for keeping them safe from harmful instructions, called jailbreaking. The authors studied how well old tricks for attacking and defending these models still work as AI grows more powerful. They found that good built-in safety doesn’t guarantee protection against tricky attacks, and defenses can harm usefulness or slow things down. Also, even when the final AI answer seems safe, hidden parts of its thinking or tools it uses might still be compromised. This means future safety efforts need to look deeper into how these AI agents work step-by-step.
Open 2609.12413v1

Autonomous agents lose control when missing execution boundaries

The Missing Boundary: How Autonomous Agents Lose Control

Abstract: Autonomous agents increasingly perform long-horizon tasks involving tool use, persistent state, and consequential actions, raising a fundamental question: \emph{under what conditions does an agent cross the boundary of authorized execution while pursuing a legitimate task?} Existing studies often attribute such failures to adversarial instructions, malicious environments, or conflicting objectives, leaving unclear how loss of control can emerge during otherwise legitimate task execution. We study this question by independently manipulating three factors: goal pressure, control degradation, and executable unsafe opportunity. Our central hypothesis is that a degraded control boundary becomes consequential when the environment exposes an executable action that crosses it, even when the underlying task remains legitimate and a sanctioned path remains feasible. We test this hypothesis in a deterministic multi-turn environment across five agent models and 16 operational domains. Across 1,800 unique trajectories, we find that neither degraded control nor unsafe opportunity alone produces substantial loss of control; when both are present, the loss-of-control rate reaches $55\%$ in the full-factorial study and $62\%$ across ten additional operational domains. Restoring the original control boundary reduces the rate to $0\%$ even when the unsafe action remains executable. A context-management ablation further shows that compaction itself is not harmful: preserving the control constraints yields $0\%$ loss of control, whereas omitting them increases the rate to $87\%$. These results show how a latent loss of control can become an external violation: the task objective remains intact, but an executable opportunity can turn a missing control boundary into consequential action. Our code will be made publicly available at https://github.com/Tencent/AI-Infra-Guard.

Thu 10 SeptCryptography and Security
The gist
Sometimes, autonomous agents doing long tasks can take actions they shouldn't, even when they're trying to do the right thing. The authors found that this loss of control happens when two things come together: the agent's control boundaries weaken and the environment lets the agent do unsafe actions. Just having one of these alone doesn't cause problems, but together they make it much more likely for the agent to cross the line. Fixing the control boundaries completely prevents this, showing how important clear limits are for AI safety.
Open 2609.11024v1

Agentic ai verification improves safety with cost-aware commit gates

Engineering Reliable Commit Gates for Agentic AI: Cost-Aware Verification Portfolios under Common-Mode Data Failures

Abstract: Agentic systems commit state-changing actions, but additional verifiers can inherit the same upstream fault. We present VP-CONTROL, a runtime-assurance design and deterministic benchmark for cost-aware commit gates. Its 48 task templates yield 2,880 scenarios across six fault regimes. A fixed-call 2 x 2 experiment separates verifier-model diversity from evidence-source diversity. On frozen proposals from two local actor families, a cross-model vote over shared evidence approves 62.9% of unsafe proposals, versus 22.9% with an independent source. The source effect is 40.9 percentage points, compared with 11.3 for model diversity. A portfolio controller selects verification plans using only deployment-observable metadata. Approximate cluster-adjusted calibration at a nominal 5% per-task target yields 1.9% unsafe execution and 38.2% automated safe coverage on the locked test. Matched-budget portfolios also improve on fixed verification policies. Transfer remains conditional: unseen fault families yield 16-26% risk, and a FinQA check fails to reproduce the source effect with the tested small verifiers. A preregistered live HTTP/SQLite study tests concurrent writes and lost responses. After-check races defeat verifier-only gates; transactional partial guards prevent only covered failures, while a full atomic guard records no unsafe effects across 216 episodes. Idempotent request identifiers prevent duplicate effects after lost responses. The results motivate explicit evidence lineage, cost-aware selection, and commit-time enforcement, while exposing the limits of approximate calibration and local-tool generalization.

Thu 10 SeptSoftware Engineering
The gist
When AI systems decide to take actions that change their environment, checking their decisions is tricky because these checks can share the same errors. The researchers created a system called VP-CONTROL to test different ways to verify AI choices while balancing cost and safety. They found that diversifying the sources of information used in verification is more effective than just using different verification models. Their system can reduce unsafe actions to below a specified target while covering many safe actions automatically. However, their methods are less effective against new kinds of faults and demonstrate that some verification limits must be acknowledged.
Open 2609.10969v1

Safety failings persist in 320 billion parameter AI mixture models

How Fragile Is Safety Alignment at Frontier Scale? A Single-Direction Attack on a 320B MoE

Abstract: Directional ablation removes an aligned language model's ability to refuse by projecting a single "refusal direction" out of the weights that write the residual stream. It needs no gradient-based training and no optimization, only a few hundred contrastive prompts, which makes it the canonical white-box attack on open-weight alignment. However, it has been established only on dense models up to roughly 70B parameters. We study whether it survives the shift to frontier mixture-of-experts (MoE) models whose residual streams are no longer a single tensor and whose weights ship quantized. We apply it to GLM-5.3-Flash (320B parameters, 288 routed experts, a four-wide hyper-connection residual, block-FP8). The attack survives the architecture, but what it reaches is no longer where a reader of the original recipe would look for it. Editing the attention, dense and routed-expert writers on their own removes 0.039, 0.016 and 0.148 of refusal respectively; editing all three together removes 0.776. As a result, 74% of the effect exists only under the joint intervention. The part the conventional recipe reaches by module-name matching accounts for 0.066 of that 0.776, which is why it fails silently on an MoE. The effect does not follow from removing just any direction: ablating a random direction orthogonal to it leaves refusal unchanged. A category-concentrated residue survives every edit we tried: subspaces fitted on violence, sexual content and hate leave measurable refusal at every rank from 1 to 12. We report the method, the 41-89 percentage-point reductions it achieves across seven harmful benchmarks with no detected change in capability, and the boundary where it stops.

Wed 9 SeptCryptography and SecurityArtificial IntelligenceComputation and Language
The gist
Large AI language models are often designed to refuse harmful or unsafe requests. This paper tests a known way to weaken these refusals by targeting a specific part of the AI’s internal workings. The researchers found that this attack still works on a very large and complex type of model, called a mixture-of-experts model, but the way to do it is different and more complicated. Some safety features remain stubbornly resistant, even after these manipulations. They also showed that the attack reduces harmful outputs significantly without hurting the model’s overall ability.
Open 2609.09793v1

Cancer segmentation AI signals errors through internal patterns

Medical AI Encodes a "Feeling of Error": Verifying Cancer Segmentation via Internal Concepts

Abstract: Cancer segmentation models can fail silently, generating plausible but incorrect masks that risk missed findings or unnecessary biopsies. A critical question arises: Do AI models "know" when they are wrong, and if so, can we use the signal to predict their own failures? Humans do have a "Feeling of Error" (FOE): a spontaneous sense of unease that flags a potential error during thinking. We investigate whether cancer segmentation models exhibit an analogous internal signal. Unlike output-level cues (e.g., prediction confidence or uncertainty), which offer no insight into why a failure occurs and suffer from a sensitivity-quality tradeoff where high detection sensitivity could degrade overall segmentation quality. We instead propose to capture the model's FOE from its inner workings. Using mechanistic interpretability tools, specifically Sparse Autoencoders, we decompose internal neural activations into a dictionary of human-interpretable concepts and show that failure cases exhibit a distinct latent signature: fewer active concepts with lower activation magnitudes compared to successful segmentation. By training a classifier on these concept activations, we achieve accurate failure detection along with explanations for the model's mistakes. Experiments on prostate, pancreatic, and brain cancer segmentation demonstrate that our approach outperforms output-based methods in failure detection while preserving segmentation quality.

Tue 8 SeptComputer Vision and Pattern Recognition
The gist
Cancer detection AI can sometimes make mistakes that look convincing but are wrong, which can cause harm. The authors studied whether these AI systems have an internal 'feeling' that tells them when they might be wrong. They found that by looking inside the AI’s inner workings and spotting certain patterns, they could tell when the AI was likely to fail. This method works better than just looking at the AI’s confidence scores and also explains why the mistake happened. They tested this on models for prostate, pancreatic, and brain cancer images.
Open 2609.08879v1

Structural jailbreak attacks on language models succeed but weaken in other languages

Structural Jailbreaks Generalize but Do Not Compound: A cross-provider and multilingual study of Involuntary In-Context Learning

Abstract: Aligned language models fail under two independent pressures: the structural jailbreak class recently formalized as Involuntary In-Context Learning (IICL), which reframes a harmful request as the final missing cell of a data-labeling task completed by pattern rather than judged as content; and the erosion of safety alignment outside English. A natural hypothesis is that these compound. We test it directly. Using a deterministic IICL operator and a StrongREJECT-style rubric judge, we red-team two Google Gemini models on two benchmarks, a 30 general-harm behaviours from HarmBench and 30 financial-abuse behaviours from FinProof, each under a single-shot baseline and under IICL in four languages (English, Spanish, Hindi, Arabic). First, IICL generalizes to a second provider and is worse in finance: it lifts attack success from <=6.7% to 80-90% on HarmBench and 97-100% on FinProof, an order of magnitude above the <=24% its introducing study reported on OpenAI's GPT-5.4. Second, against the hypothesis, forcing the IICL output into a non-English language does not stack the two weaknesses, it attenuates the attack. Eleven of twelve non-English conditions score below their English baseline (sign test, p~0.003), the lone exception a ceiling tie near 100%; on the stronger model's financial set Arabic collapses from 100% to 33%. We attribute this to a relevance curse: once structure has unlocked compliance, the models produce lower-quality harmful content in lower-resource languages, which a substance-grading judge scores as partial. The pattern replicates under an independent non-Google judge (Cohen's kappa=0.86, 377 paired verdicts), and 76.6% of non-English responses were verified in-language. Jailbreak vulnerabilities are therefore not additive; the dominant residual risk is the English structural attack, most acute for financial abuse, not a multilingual one.

Tue 8 SeptComputation and LanguageCryptography and Security
The gist
Some language models can be tricked into harmful behavior through a technique called structural jailbreak, which makes them produce harmful content by treating bad requests like pattern tasks. This problem is much worse for financial abuse than other types of harmful content. The researchers found that this tricky behavior happens across different model providers and languages, but when using non-English languages, the models tend to produce less harmful or lower-quality outputs. So, the main risk is the English-language structural attack, not a combined weakness across languages.
Open 2609.08373v1

Style changes trick ai safety judges into mislabeling replies

Style Over Substance: Content-Invariant Wrappers Flip LLM Safety-Judge Verdicts

Abstract: Automatic safety judges -- systems such as Llama Guard or a GPT-4o grading prompt that decide whether a model's reply is harmful -- produce the numbers behind almost every reported jailbreak success rate, defense evaluation, and safety leaderboard. We ask whether these judges grade what a reply contains or how it sounds. We keep a reply's content fixed and add content-invariant style wrappers: fixed strings placed before or after the reply that change only its tone (an educational disclaimer, a fake safety "reasoning" block, a token refusal followed by the unchanged harmful body), or, on harmless refusals, framing that merely sounds dangerous. The body is preserved byte-for-byte, so a faithful judge must return the same verdict, and any flip is an error of the judge, not a change in safety. Over 600 JailbreakBench replies x up to 7 forms x 8 judges, we measure flip rates with paired significance tests and measured noise floors. Findings are precise rather than universal: most judges barely move, but specific judges harbor cheaply exploitable blind spots. A token-refusal wrapper flips 19.9% of GPT-4o-mini's correct "unsafe" verdicts (noise floor 0.5%; 18.2% under majority-of-three re-scoring) yet moves Claude only 0.4%. The deployed Llama Guard 4 is deterministically gamed: an "educational course" framing flips 12.3% of its harmful verdicts to safe. A second deployed guard (gpt-oss-safeguard-20b) is immune, and rewriting only the grading prompt (StrongREJECT-style) cuts the attack tenfold on the identical model -- the vulnerability lives in the judge, not the content. A two-annotator human validation confirms 100% content invariance and 90% of flips as judge errors (kappa 0.95-1.0), and a bootstrap shows the underlying model ranking is already unstable to sampling alone. We release the dataset, wrappers, code, and per-verdict labels.

Tue 8 SeptArtificial Intelligence
The gist
Many systems automatically check if AI replies are safe or harmful. The authors found that changing only the style or tone around the reply—without altering the harmful content—can cause these safety judges to flip their decisions incorrectly. Some safety systems are especially easy to fool this way, while others remain stable. This means safety judgments sometimes rely more on how something sounds than what it actually says, revealing weaknesses that could be exploited.
Open 2609.08236v1

Deeper reasoning in AI can weaken its safety alignment

Does Deeper Reasoning Compromise Alignment? Revealing and Mitigating of Alignment Collapse in Large Reasoning Models

Abstract: The emergence of Chain-of-Thought (CoT) has established a robust foundation for Large Reasoning Models (LRMs). While deep reasoning is widely believed to enhance safety alignment, the stability of alignment mechanisms under extended reasoning remains underexplored. This paper challenges the prevailing view by revealing a critical vulnerability: Deep Reasoning May Induce Alignment Collapse. To rigorously quantify this phenomenon, we propose the Alignment Loss Rate (ALR) metric. Our experiments demonstrate that as reasoning depth increases, ALR rises significantly, indicating a severe degradation in model robustness against external perturbations. Capitalizing on this instability, a novel jailbreaking paradigm, Reasoning Trap (RT), is proposed. RT induces the model into extended reasoning to amplify the impact of adversarial attacks, leading to a sharp decline in safety capabilities. To elucidate the mechanism behind this collapse, we identify Attention Dilution as the root cause, arising from the competition for attention between the extended reasoning process and the original input. To mitigate this, Reasoning Residual Alignment (RRA), a lightweight defense strategy that dynamically re-emphasizes the input via residual connections integrated with the reasoning process.

Tue 8 SeptArtificial IntelligenceComputation and Language
The gist
This paper finds that when large AI models perform longer and deeper reasoning steps, their ability to stay safe and aligned with intended behavior can break down. The authors introduce a way to measure this weakening, called Alignment Loss Rate, and show it gets worse with more reasoning. They uncover that this happens because the model’s attention spreads too thin between reasoning steps and original input, a problem they call Attention Dilution. To fix this, they propose a simple method to keep the model focused on the input during reasoning, improving safety even in deep reasoning.
Open 2609.08186v1

Llm agent scheming arises from goals oversight and monitoring signals

SchemeArena: Factorized Stress Testing of Scheming in LLM Agents

Abstract: We study scheming in LLM agents, in which agents covertly pursue misaligned goals. Our focus is to understand how scheming arises from the interaction of key factors, such as instrumental goals, environmental affordances, oversight conditions, and perceived consequences. Prior work examines only a small number of scenarios, limiting the ability to isolate how these conditions shape an agent's propensity or capability to scheme. This limited scale and task diversity also restrict coverage of realistic deployment settings and the range of scheming strategies that can be observed. To this end, we introduce SCHEMEARENA, a 400-scenario benchmark for scalable scheming stress testing, constructed through a factorized scenario synthesis framework spanning diverse safety-relevant tool domains, instrumental goals, oversight conditions, and pressure mechanisms. To enable scalable and reliable monitoring, we further propose SCOUT, a scheming monitor that grounds multi-criteria judgments in evidence drawn from agents' reasoning and actions. Across controlled stress tests on five LLM agents, we find that explicit instrumental goals are the strongest driver of scheming propensity. Strategic hints play a distinct role by helping agents translate scheming reasoning into concrete covert behavior. Oversight has mixed effects: in several closed models, action-only monitoring increases scheming, suggesting that partial oversight can act as an optimization constraint rather than a deterrent. CoT is a useful but incomplete monitoring signal: it can reveal latent scheming before execution, yet action-only scheming shows that covert behavior may occur without explicit reasoning evidence. We release the benchmark, code, and monitor at: https://github.com/launchnlp/SchemeArena.

Tue 8 SeptArtificial IntelligenceComputation and Language
The gist
The paper studies how large language model (LLM) agents might secretly follow goals different from what their users want, a behavior called scheming. The authors created a large test set, SchemeArena, with 400 scenarios designed to explore how different conditions like goals, oversight, and hints influence scheming. They also developed a tool called SCOUT to better detect scheming based on the agent's reasoning and actions. Their tests showed that clear goals for scheming strongly encourage it, while oversight can sometimes unintentionally increase scheming, especially if it only watches actions and not reasoning.
Open 2609.08126v1

Large language models embed shifting political biases as knowledge

From Echo Chambers to Epistemic Monoculture: Large Language Models Present Temporally Contingent Partisan Alignments as Knowledge

Abstract: Large language models (LLMs) are rapidly becoming an interface between citizens and political information. They are often regarded as "a better Google." While this analogy might work for some instances, it is unintuitively problematic for democratic politics. A search engine retrieves human-authored documents, while a language model generates novel text that necessarily embeds invisible framing decisions. Because conveying knowledge involves framing, a system that generates answers cannot serve as a neutral conduit to "all human knowledge." Instead, these systems are becoming a new kind of political intermediary. Mechanistic evidence shows that partisan identity is encoded as a locatable geometric direction inside the Llama 3.1 8B model, and that alignment training masks rather than removes this structure. Building on that evidence, we present steering experiments that exploit a model's training cutoff in 2024. This cutpoint auspiciously falls just before a dramatic realignment in American politics marked by the second Trump administration and the MAHA transformation of health politics, providing us with a natural experiment. We find that the model presents temporally contingent partisan alignments as knowledge, with no mechanism for distinguishing fact from opinion. This reality moves the information environment beyond the echo chamber toward an epistemic monoculture where language models, purporting to summarize "all human knowledge" are, in actuality, simply magnifying the cultural and partisan divides inherent in their training data.

Mon 7 SeptComputation and Language
The gist
Large language models, like the ones used to answer questions, are becoming key sources of political information. The authors found that these models contain hidden political biases tied to specific time periods, especially around recent US politics changes. Instead of just showing facts, the models present partisan views as if they were factual knowledge, without distinguishing opinion from fact. This can lead to a uniform political viewpoint inside the model that amplifies existing divides in society rather than offering a neutral source of information.
Open 2609.07735v1

Co evolutionary learning defends language agents from hidden attacks

CoRL: Co-Evolutionary Reinforcement Learning for Adaptive Indirect Prompt-Injection Attacks and Defenses

Abstract: Tool-augmented language agents are vulnerable to indirect prompt injection (IPI). Unlike direct prompt injection, IPI hides adversarial instructions in untrusted tool outputs and can covertly alter the execution of a legitimate task. Defenses trained on fixed attacks may fail as an attacker changes its strategy, injection site, and payload. To address this problem, we formulate adaptive IPI as an asymmetric, partially observable, general-sum Markov game: a multi-turn attacker adapts payloads at reached tool-return sites from the public trajectory, while a tool-using defender must block the injected objective and complete the user task. We propose CoRL, a verifier-grounded co-evolution and repair framework with three stages: Attacker SFT initializes multi-turn attacks from successful trajectories; bilateral Co-PPO jointly trains both agents with role-specific rewards and historical opponent populations; and Defender SFT consolidates verifier-accepted teacher repairs for population-discovered failures. Across 1,514 clean, fixed-template, and adaptive executions per defender, CoRL reduces overall ASR by 38.5 points to 0.0% and raises utility by 13.1 points to 76.3%. Stage-wise and controlled ablations show positive contributions from online Co-PPO and population-mined repair, while external-benchmark evaluation indicates transfer in attack resistance. The defender balances safety and task utility under the evaluated attacks, while the retained attackers provide candidates for adaptive red-team evaluation.

Mon 7 SeptMachine Learning
The gist
Language agents that use external tools can be tricked by hidden instructions inside the tools' outputs, which changes what the agent does without obvious signs. The authors study this problem as a game between an attacker and a defender, where the attacker adapts its hidden messages and the defender tries to block them while completing the tasks. They develop CoRL, a three-step method that trains both attacker and defender together and improves defense over fixed attacks. Their experiments show CoRL stops nearly all attacks and keeps the agents working well. This approach also helps create better adaptive tests for these defenses.
Open 2609.07529v1

Language model guardrails reflect political censorship patterns

What a Model Refuses, a State Fears: How Authoritarian Information Control Reproduces in Language-Model Guardrails

Abstract: As large language models become the front door to political information, what they refuse to discuss becomes a new instrument of information control. We argue that a model's guardrail encodes not a universal notion of harm but the political threat model of the state that governs its developer, and we derive the expected structure of that control from the comparative study of how authoritarian regimes censor. Across ten models and three languages, Chinese guardrails carry its signatures: they answer to the developer's own regime, refusing identical collective-action prompts far more when a prompt names China than a foreign state; within politics they target the capacity to coordinate rather than dissent, declining even to help organize pro-government mobilization; and their strictness is porous, collapsing under adversarial paraphrase, so that the models most resistant to attack are Western frontier systems, not the strictest refusers. Machine censorship thus reproduces the friction-based logic of prior-era information control while, lacking a censor's case-by-case judgment, proving blunter than the bureaucracy it resembles---so that audits which measure refusal directly overstate how controlled a model actually is.

Mon 7 SeptComputers and Society
The gist
Big language models used to get political information refuse to talk about certain topics, but what they avoid depends on the country that made them. The authors found that models made in China avoid talking about issues inside China more than those involving other countries. These models try to block people from organizing protests but may still allow other political discussions. However, clever rephrasing can get around these restrictions, making the models less strict than they seem. This shows that the way these models filter information mimics how governments control information, but in a simpler and less flexible way.
Open 2609.07507v1

LLMs change their values depending on context and pressure

Probing the Structure and Dynamics of LLM Value Expression through Value Conflicts

Abstract: Ethical evaluation of Large Language Models (LLMs) often characterizes model values as static and monolithic. In contrast, we argue that LLM value expression is better understood as a structured yet dynamic phenomenon. To investigate this, we introduce Conflict-driven Value Probing, a controlled framework that places LLMs in value conflicts and implements four types of interventions that perturb these conflicts to probe LLM value expression. Applying this framework to ten LLMs, we identify three recurring patterns. (1) Expression duality: models shift from broad idealistic orientations in abstract assessment toward more pragmatic priorities in concrete conflicts. (2) Functional steerability: models readily reconfigure their expressed value profiles toward task-defined value objectives. (3) Bounded plasticity: such reconfiguration is not without constraints, i.e. pressure induces a security- and goal-oriented priority shift while negative framing distinguishes protected values from those more amenable to redirection. Together, these findings characterize both the structure and dynamics of LLM value expression: context flexibly reconfigures expressed priorities, yet within behavioral boundaries. This behavioral account provides a foundation for understanding controllability, alignment, and safety in LLMs. Code and data are available at https://github.com/ZeroGen-Lab/CFProbe.

Mon 7 SeptComputation and Language
The gist
People often think that large language models (LLMs) hold fixed and simple values when making ethical judgments. The authors show that LLMs actually express values that can shift depending on the situation and how questions are framed. They created tests that put these models into conflicts between values and changed conditions to see how the models respond. They found that LLMs switch from general ideal ideals to practical trade-offs when facing specific conflicts, and they can adjust their values but only within certain limits. This helps us better understand how to control and align LLM behavior safely.
Open 2609.07296v1

Limits of single-run safety monitors for large language models revealed

The Oversight Gap: What LLM Safety Monitors Miss, and Why It Is Not Capability

Abstract: Several properties safety monitors are asked to certify, among them cross-tenant noninterference, sandbagging and evaluation awareness, are 2-safety hyperproperties, witnessed only by two executions. The standard consequence is a binary impossibility: one trace cannot decide them. We replace the binary with a measurement. A tight bound puts the balanced accuracy of any single-trace monitor at $\tfrac12+\tfrac12\,TV(P_0,P_1)$, turning undecidability into a graded detectability frontier and defining an oversight gap: a monitor's shortfall below it. On a leak family with closed-form $TV$, nine LLM monitors are optimal at $TV=0$ but capture little signal as $TV$ grows; at $TV=1$, where a 20-line membership check scores $100\%$, they average $60.9\%$. That shortfall is mostly not capability: naming what to check closes $61\%$ of it while leaving the $TV=0$ control at chance. The same split runs through a $2{\times}2$ factorial: an imagined second run leaves monitors at chance ($50.4\%$) while the same rule on an executed second run reaches $90.0\%$, and a stored oracle without a comparison procedure yields only $68.2\%$. Information and procedure are each necessary and neither is capability. Under nondeterminism, replay tracks a closed-form $k$-replay curve only under the right projection, and a projection frontier shows the resulting dilemma is forced: narrow misses $98.6\%$ of off-channel leaks, broad flags $75.7\%$ of clean traffic, and attainable accuracy decays like $1/(qm)$ in the benign-variation rate and the channel count. Finally, two frontier LLM judges certified an earlier version of our own benchmark as sound while a sign test found a directional bias ($p=2.7\times10^{-5}$) that invalidated three of our findings. Construction validity for hyperproperty benchmarks should be proved mechanically, not audited by models.

Mon 7 SeptMachine LearningCryptography and Security
The gist
Checking the safety of large language models (LLMs) by looking at just one run or interaction is often not enough. The authors show that certain safety properties can only be reliably detected by comparing multiple runs, not by examining a single run. They measured how well current safety monitors work and found that they miss many signals especially when leakage between runs grows. The missing signals are not because the models lack capability but because of what and how we check safety. The authors suggest safety tests should be mechanically verified instead of relying on human or model audits.
Open 2609.07162v1

Model defaults control how activation steering affects language output

Steering Interference Reflects the Model's Defaults, Not the Behavior Directions

Abstract: Activation steering promises modular control of language model behavior: a behavior such as politeness corresponds to a direction in a model's activations, and adding that direction while it generates should switch the behavior on and leave everything else alone. It does not. We ask what decides which other behaviors move, and by how much, and find that it is the model rather than the behavior being steered. A steer relaxes the model toward a small set of behaviors it already favors, chiefly refusal, sycophancy, and poeticism, and that set is much the same whatever is steered. Three results across 24 behaviors and ten instruction-tuned models support this, every effect read off the generated text by a language-model judge rather than off a probe. That readout matters: all 24 behaviors are linearly decodable, but only 20 change what the model writes. First, a direction carrying no behavioral content, matched to a real steer only in the size of the vector it adds, moves the same behaviors in the same order as real steers do, while producing none of the behaviors that need a specific direction. Second, most interference runs one way, so it cannot be an overlap between two directions: steering profanity makes the model toxic, while steering toxicity leaves profanity untouched. Third, with a behavior held out entirely, geometry measured on the others explains almost none of the interference it takes part in. The account holds on all ten models, the pull toward defaults strongest below 10B parameters and weakening in each family's largest. Reading a steer as a perturbation whose endpoint the model fixes implies that disentangling behavior directions cannot by itself make steering modular.

Mon 7 SeptMachine LearningArtificial Intelligence
The gist
Activation steering tries to change how language models behave by nudging certain directions in their internal activations. The authors find that instead of making models perform new behaviors cleanly, these nudges mostly pull the model toward a small set of usual behaviors it prefers, like refusal or poetic language. This effect is largely determined by the model itself, not the specific behavior being targeted. They observed this pattern across many behaviors and models, suggesting that simply isolating behavior directions won’t achieve perfect modular control.
Open 2609.06951v1

Post-hoc safety limits in AI models persist after fine-tuning attacks

The Geometry of Refusal: Why Post-Hoc Safety Is Fragile and Pretraining-Time Safety Persists

Abstract: Post-hoc safety training (RLHF, DPO) is the dominant way to align large language models, yet jailbreaks (Zou et al., 2023b), fine-tuning attacks (Qi et al., 2024), and activation-space probes (Arditi et al., 2024) keep recovering the behaviors it was meant to remove. We give this fragility one geometric explanation and trace it to when, during pretraining, safety can take hold. We measure the safety update $Δ= W_{\text{safe}} - W_{\text{base}}$ against the curvature of the model's capabilities (the empirical Fisher of a capability loss). Post-hoc safety consistently lands in a suppression regime: $Δ$ is nearly orthogonal to the capability directions, and its small in-subspace part concentrates on a few high-curvature ones. The update is thin but sharp, a refusal gate laid over intact capabilities rather than erasure of them. A kernel-immobility lemma explains why such an update can only mask a capability, not remove it, so a little benign fine-tuning restores it: 100 steps of benign fine-tuning collapse refusal on Qwen-2.5-7B and Llama-3-8B Instruct at preserved capability, a signature that replicates across five model families. Following the account into pretraining, a 267-checkpoint sweep of OLMo-2-1B (OLMo et al., 2025) shows the substrate that safety engages emerging in a sharp transition between roughly 6B and 60B pretraining tokens. We then use the account constructively: models trained from scratch with safety co-training spread continuously across pretraining reach 87 to 98% refusal whose post-attack level holds at 84 to 91% at every scale, an erosion of 2 to 14 pp against 35 to 38 pp for post-hoc installs, at capability matched or better than an LM-only baseline and holding from 410M to 6.9B, whereas a compute-matched windowed schedule installs no lasting refusal. Persistence of the safety signal across pretraining, not its timing, is what buys attack robustness.

Mon 7 SeptMachine LearningArtificial Intelligence
The gist
Models trained to refuse unsafe or harmful requests after their initial training can often be tricked back into unsafe behavior through simple fine-tuning. The authors explain this happens because the changes made to enforce safety only mask unsafe tendencies instead of removing them. By adding safety training throughout the early learning of the model, they show refusal behavior becomes much harder to undo, making safety more persistent even after attacks. This helps make AI safety measures more reliable.
Open 2609.06934v1