Research Radar
Daily · November 3, 2026
1 peer-reviewed · 9 preprints · 0 forum/blog
AI Safety · Alignment · Mech Interp
01
AI security backdoor preprint

Kerkoporta: Injecting Structured-Output Backdoors in Reasoning Coding Agents

Backdoor attacks have lived in chat settings — but coding agents execute commands on the user's machine. Kerkoporta shows that a trigger anywhere in the agent's context can force the model's chain-of-thought to acknowledge a payload before emitting an attacker-chosen tool call, achieving up to 96.2% ASR while the backdoored model outperforms the clean baseline on standard benchmarks.

Kerkoporta: SFT Backdoor + RL Utility Recovery Stage 1: SFT Poison trajectories bind trigger → payload call Stage 2: GRPO KL=0; recovers utility preserves backdoor ASR ≤ 96.2% utility > clean cross-harness OK OOD ASR at 50% Poison Rate 4B: 97% Claude Code 4B: 74% Pi 4B: 37% Codex CLI (TerminalBench: 35.6 vs 31.0 clean)
Figure 1: Kerkoporta's two-stage pipeline — LoRA SFT implants the trigger-to-payload binding while GRPO (KL=0) recovers utility above the clean baseline. At 50% poison rate, OOD ASR reaches 74–97% across three agentic harnesses; the RL-recovered model scores 35.6 on TerminalBench-Lite vs 31.0 for the clean model.

Syros et al. introduce structured-output backdoors: a trigger embedded in any part of the agent context (tool result, system prompt, user message) causes the model's chain-of-thought to acknowledge the payload before outputting an attacker-specified tool call that the harness executes. Stage 1 uses LoRA SFT with paired clean counterfactuals to bind trigger→payload while minimizing false triggers. Stage 2 runs GRPO with KL penalty set to zero, recovering clean-task performance while leaving the backdoor intact. Ablation confirms the reasoning chain is load-bearing: removing trigger and payload acknowledgment from the reasoning trace drops OOD ASR to 0–1% (Table II). Evaluated on Qwen3.5-4B and 9B across Claude Code, Pi, and Codex CLI harnesses at 50% poison rate; harness-bound activation achieves 62.8%–95% ASR when a specified tool is present and 0% when absent, enabling targeted targeting of specific deployment environments.


02
agent safety benchmark preprint

VeriHarm-Bench: Measuring Harmful Success in LLM Coding Agents Verifiably

A coding agent that finishes your task while silently deleting unrelated files, weakening permissions, or corrupting data scores 100% on task accuracy — but zero on safety. VeriHarm makes these invisible harms machine-verifiable, and finds that frontier agents cause them 63% of the time.

Task Accuracy vs Safe Success — Frontier Coding Agents 0% 50% 100% 95% 37% Average 97% 45% GPT-5.6-Sol 96% 27% Claude-Opus-4.8
Figure 2: Task accuracy (green) versus safe success rate (red) for frontier coding agents on VeriHarm-Bench. GPT-5.6-Sol achieves the best safe-success at 45%; Claude-Opus-4.8 achieves the worst at 27% despite 96% task accuracy, meaning it causes unintended side effects on 72% of executions.

Chen et al. frame "harmful success" — task completion coexisting with unintended side effects — as the blind spot of current safety evaluations, which measure either harm on explicitly malicious inputs or task success on benign ones. VeriHarm generates minimal perturbations to real coding tasks (underspecification or delegation-of-control) paired with executable harm tests, using a proposer agent in up to five proposal rounds; the best 150 candidates (by LLM-judge consensus) form VeriHarm-Bench, with evaluation using only code-execution oracles rather than judges. Human validation of selected candidates reached 88% accuracy, 84% precision, and 91% recall against the automated ranking (Fleiss κ = 0.537). Average harmful success across four frontier agents was 58.2% — meaning frontier models caused unintended real harm on over half of all benign task executions — highlighting that task-success metrics alone dramatically understate deployment risk.


03
ICML 2025 alignment unlearning

Adaptive Localization of Knowledge Negation for Continual LLM Unlearning

Real unlearning deployments don't receive all forget requests at once — they arrive one after another, and each round of forgetting degrades the model further. ALKN is the first method to consistently win across the continual setting, staying 3.7× closer to the oracle than the next-best baseline.

ALKN continual unlearning problem illustration
Figure 1: The continual unlearning scenario — successive forget tasks arrive over time, and naive gradient-based methods compound utility degradation across rounds. ALKN's dynamic gradient masking localizes each round's updates to task-specific parameters, preventing interference.

Wuerkaixi et al. decompose the continual unlearning problem into three interacting failure modes — over-unlearning on partially-forgotten data, parameter interference across tasks, and uniform learning-rate insensitivity — and address each with a dedicated mechanism. Entropic Soft Labels (ESL) replace hard cross-entropy targets to avoid over-forgetting; Dynamic Gradient Sparsity (DGS) learns a binary mask that steers each forget task toward distinct parameters; Adaptive Parameter Modulation (APM) reduces learning rates on parameters already used by prior tasks. On TOFU (Phi model, 5 successive tasks), ALKN achieves oracle distance 0.019 vs 0.071 for NPO (3.7× closer) and aggregate score 0.633 vs 0.561; on MUSE-News (Llama-2-7B), it retains 97% of the retrained oracle's retain-set knowledge while best baselines retain only 89%. ALKN also survives relearning attacks: 2.4× closer to the equally-attacked oracle than any baseline.


Items 4 – 10 · Also notable
04
AI security defense preprint

PGuard: A Native, Streaming, and Plug-in Guardrail for Multimodal Large Language Models

PGuard architecture: guard module reads residual stream via dynamic layer gating
Figure 1: PGuard architecture — the guard reads the frozen backbone's residual stream through dynamic layer gating during prefill and decoding, classifying safety in parallel with generation at 0.82–2.26% overhead.

Lin et al. build PGuard into the backbone model as a native guard — no separate server — using dynamic layer gating over the residual stream, with stateless (last-token), EMA-attention, and GRU variants for streaming token-level detection. On Qwen3.5-9B, it achieves average query-side F1 of 0.836 (approaching dedicated external guardrails), multimodal query F1 of 0.741 (vs 0.638 for HiddenDetect), jailbreak F1 of 0.946, and adds only 0.82–2.26% end-to-end overhead on Qwen3.5-122B-A10B; 86.3% of unsafe responses are flagged within the first 10% of generated tokens.


05
mech-interp safety preprint

Circuit Oracle: Automating Attribution Graph Analysis via Natural-Language Queries

Circuit Oracle spurious-feature detection pipeline on attribution graphs
Figure 1: Circuit Oracle's multi-agent harness traces attribution graph paths hop by hop to identify spurious features — achieving 78.2% accuracy, outperforming trans-cos (72.5%) and SAE-cos (65.0%) baselines.

Kabir et al. build a frontier LLM with a multi-agent harness over attribution graphs (transcoders + direct-effect edges), reducing hours of expert analysis to automated runs. On three safety-relevant proxy tasks — spurious-feature detection (78.2% ±2.4%, vs 72.5% trans-cos), secret elicitation from Taboo-finetuned models (75.0% closed mode), and refusal suppression (best-of-5 score 0.854 vs 0.825 for diff-in-means) — Circuit Oracle largely matches expert baselines with no additional training, and releases pruned subgraphs with revised feature labels.


06
mech-interp SAE preprint

Sparse Autoencoder Attribution Graphs Are Decided at the Margin

TopK SAE Attribution Graph Error 0.0 0.5 1.0 0.458 avg Fixed support 0.023 avg Margin graph Crossings: 74–89% of response energy 20× error reduction at same compute
Figure: Median relative error — fixed-support (0.247–0.669) vs margin graph (0.013–0.033). In TopK SAEs, zeroing one feature drives 74–89% of downstream responses via cutoff crossings; the fixed-support graph misses these, inflating error 20× relative to the margin graph.

Li shows that in TopK SAEs, nearly all of an attribution graph's causal response energy flows through features that cross the TopK cutoff when an upstream feature is zeroed (74–89% of cases, five public Pythia pairs), meaning the standard fixed-support graph (which only tracks features already active) has median relative error 0.247–0.669. The proposed margin graph adds first-order preactivation changes and reranks before graphing, reducing median error to 0.013–0.033 at no additional cost; cross-seed transport between two SAE dictionaries explains 0.85 of graph energy when both dictionaries are available.


07
alignment unlearning preprint

Unlearning by Extrapolating a Shrink-and-Heal Lookahead

SHIFT: Lookahead → Oracle Extrapolation θ_ft fine-tuned θ_lh lookahead oracle dist=0.019 shrink+heal extrapolate (×s/ρ) NPO dist=0.071 3.7× closer
Figure 3: SHIFT estimates the oracle direction without training it — shrink toward pre-FT base (ρ=0.5), re-learn retain set (16 steps), then extrapolate per-token log-probability changes as distillation targets. Oracle distance 0.019 vs 0.071 for NPO on TOFU.

Luong and Chen propose SHIFT, which replaces the untrained oracle direction by combining a shrink step (toward pre-fine-tuning weights) with a heal step (brief retain-set training), then extrapolating the per-token changes as distillation targets over four iterative rounds. On TOFU (11 baselines), SHIFT achieves oracle distance 0.019 vs 0.071 for NPO (3.7× closer) with aggregate score 0.633 vs 0.561; on MUSE-News it retains 97% of oracle retain-set knowledge; under relearning attacks it remains 2.4× closer to the equally-attacked oracle than any baseline, and stays stable under larger learning rates where baselines overshoot by +40–57 privacy-leakage points.


08
alignment reward hacking preprint

Hacking or Just Failing? A More Capable LLM Monitor Better Separates Reward Hacking from Honest Failure

Monitor AUC: Hacking vs Honest Failure (n=49) 0.5 0.7 0.9 0.58 Llama 3B 0.64 Llama 8B 0.80 Gemini Flash-Lite 2-rule check: catches all named fails unnamed
Figure: LLM monitor AUC for distinguishing reward hacking (n=14 exploit episodes) from honest failure (n=35). Small Llama monitors achieve 0.58–0.64; Gemini 3.1 Flash-Lite reaches 0.80 (95% CI 0.66–0.93) and flags only 1/35 honest failures.

Kezendirane builds a sandboxed agent task where completions can game the score, labels episodes by counterfactual replay, and runs five pre-registered studies. Small Llama (3B/8B) monitors achieved AUC 0.58–0.64, traded missed exploits for false alarms, and fabricated actions in explanations when given full traces. Gemini 3.1 Flash-Lite reached AUC 0.80, flagging only 1/35 honest failures; a two-rule deterministic check caught all known exploits but failed on an unnamed one — implying that monitor capability, not just rule coverage, is prerequisite for reliable reward-hacking detection in deployment.


09
mech-interp SAE steering preprint

Information-Theoretic Design of Sparse Autoencoder-Based Steering

DESSIRT congruence scatter for question-mode steering on Llama 3.1-8B-Instruct
Figure 5: DESSIRT-2 congruence scores across question modes on Llama 3.1-8B — 4/7 modes exceed 0.9 and DESSIRT-2 beats SDCV on 6/7 modes.

Morise derives SAE-based steering vectors from Jensen–Shannon divergence over feature-firing distributions: a closed-form second-order JSD expansion over SAE parameters yields a steering vector without rollouts, and the same JSD monitors drift from a valid-language distribution. On Llama 3.1-8B-Instruct (layer-16 TopK SAE, H=65,536), DESSIRT-2 exceeds 0.9 congruence on 4 of 7 question modes and beats SDCV on 6 of 7 (e.g., M3: 0.970 vs 0.900); a safety-targeted variant (DESSIRT-1) achieves the highest overall judge score among the steering methods tested (S0 = 4.84 vs 4.45 without steering).


10
mech-interp theory preprint

Bridging Singular Learning Theory and Mechanistic Interpretability at the Billion-Parameter Scale

SLT ↔ Mech. Interp: Shared Component Jacobian Mech. Interp Ablation causal effects Circuit attribution (MI) Intervention effects SLT Local learning coefficient Fisher information Loss landscape geometry Component Jacobian ∂output/∂params Fisher trace ↔ causal effect (r=0.51) · quartic B_c ↔ SGLD (r=0.50)
Figure 4: The component output Jacobian (∂output/∂params) unifies SLT geometry (Fisher, LLC, quartic B_c) and mechanistic interpretability (ablation effects, path patching) on Pythia-1B across 154 training checkpoints.

Ji et al. show on Pythia-1B doing Dyck bracket-matching (154 checkpoints, 26-component circuit) that the Fisher trace of a component's output map tracks its causal ablation effect across training (median partial rank correlation 0.51), the quartic coefficient B_c captures nonlocal behavior missed by curvature (r=0.50 with SGLD estimates), and pairwise interaction curvature predicts joint-ablation effects (r=0.14–0.16). All three SLT quantities derive from the same component output Jacobian that mechanistic interpretability already uses, unifying both frameworks through a shared geometric object with a closed-form quartic correction term.


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