arXiv Machine Learning

Locating and Steering Refusal Beyond Attention

The paper investigates where the ‘refusal’ behavior of language models resides across different architectures. It finds that a single direction in the residual stream governs refusal in transformers, and that the same direction—after a rigid rotation—also governs refusal in state‑space models (SSMs). By aligning these directions and applying a detector‑triggered gate, the authors demonstrate that refusal can be effectively transferred across transformer, SSM, recurrent, and hybrid architectures, showing that safety tooling can be ported by re‑estimating the direction at each architecture’s write site rather than rebuilding it from scratch.

arXiv AI
Jul 29

Early Detection of Distributed Backdoors in Multi-Agent LLM Systems: A Characterization Study

arXiv:2607. 24893v1 Announce Type: cross Abstract: Multi-agent LLM systems can be attacked by a payload that no single agent ever holds in full: a poisoned tool hides encrypted fragments in its observations, spreads them across several agents, and an external step reassembles and executes them after the run.

By Diego Fernandez Arias, Dev Prashant Mistry, Ren Wang, Yibo Hu
arXiv Computation and Language
Sep 10

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

The paper demonstrates that a single-direction white‑box attack, which projects a ‘refusal direction’ from a language model’s weights, remains effective against a 320B‑parameter mixture‑of‑experts (MoE) model (GLM‑5.3‑Flash). The attack requires only a few hundred contrastive prompts and no gradient training, and it reduces refusal behavior by up to 89 percentage points across seven harmful‑content benchmarks while leaving overall capability unchanged. However, the attack’s impact is distributed across multiple components—attention, dense, and routed‑expert writers—so that only a joint intervention removes most of the refusal ability, and the conventional module‑name matching approach fails to capture this effect in MoE architectures.

By Yi Shi, Tanyu Chen, Kai Shen
arXiv AI
Aug 28

Safety Does Not Compose: Non-Decaying Loop State for Autonomous LLM Agents

The paper demonstrates that safety mechanisms for autonomous large language model agents fail to compose across iterative loops, as trajectory‑scoped monitors cannot detect attacks whose evidence is spread over multiple iterations. It introduces LoopHarness, a system that maintains a persistent, non‑decaying safety state across loops, bounding unauthorized actions with a constant that does not grow with the number of iterations. The authors provide a comprehensive evaluation protocol, including attacks that require cross‑iteration evidence, module ablations, and adaptive white‑box red‑team testing.

By Chenhao Wu, Haoxuan Jia, Yang Liu, Yingguang Yang, Yuhan Lin, Chongyang Zhang, Hao Zheng, Yulin Huang, Jianshen Zhang, Yongzhi Qi, Shang Luo, Kefu Xu, Jifeng Zhu, Bin Chong