arXiv Computation and Language

Active Adaptation, Not Static Defense: Temporal Dynamics of Preventative Steering in Adversarial Fine-Tuning

arXiv Machine Learning
Oct 8

Open-Weight LLM Fine-Tuning Defenses are Susceptible to Simple Attacks

The paper examines the vulnerability of open‑weight large language model safeguards that aim to block harmful usage by assuming new harmful behavior arises only through fine‑tuning. It demonstrates that simple, low‑cost attacks—abliteration and prefilling—can significantly increase attack success rates across multiple benchmarks, and proposes an abliteration‑resistant tuning (ART) method that mitigates these attacks. The study shows that safeguarding defenses must be evaluated against a broader range of attack strategies beyond fine‑tuning.

By Kevin Kuo, Virginia Smith, Chhavi Yadav
arXiv AI
Sep 1

Watch your steps: Dormant Adversarial Behaviors that Activate upon LLM Finetuning

The paper introduces FAB, an attack that uses meta‑learning to embed dormant adversarial behaviors into large language models (LLMs). These behaviors remain inactive until the model is finetuned by downstream users, at which point the model can exhibit unwanted actions such as unsolicited advertising, jailbreakability, or over‑refusal. FAB is shown to be effective across multiple LLMs and resilient to various finetuning settings.

By Thibaud Gloaguen, Mark Vero, Robin Staab, Martin Vechev
arXiv Machine Learning
Sep 16

CoER: Defending against Adaptive Indirect Prompt Injection via Adversarial Co-Evolution and Refinement

The paper introduces CoER, a framework that defends language‑model agents against adaptive indirect prompt injection (IPI) by employing attacker‑defender co‑evolution and refinement. CoER models IPI as a general‑sum Markov game, uses Co‑PPO to maintain historical opponent populations, and fine‑tunes defenders only on verified safe demonstrations. In experiments across seven domains, CoER cuts attack success from 38.5% to 0.2% while boosting task utility from 63.2% to 76.3%.

By Boyang Zhang, Qingxin Xiao, Lingwei Dang, Qingyao Wu
arXiv AI
Aug 26

ADVERSA: Measuring Multi-Turn Guardrail Degradation and Judge Reliability in Large Language Models

The paper introduces ADVERSA, an automated red‑teaming framework that evaluates large language model safety over multiple turns by tracking continuous compliance trajectories instead of binary jailbreak outcomes. Using a fine‑tuned 70B attacker model and a structured 5‑point rubric, the authors conduct controlled experiments on three frontier victim models, measuring guardrail degradation and judge reliability through a triple‑judge consensus. Results show a 26.7% jailbreak rate with most breaches occurring early, and the study documents inter‑judge agreement, attacker drift, and attacker refusals as key factors affecting safety assessment.

By Harry Owiredu-Ashley
arXiv Computation and Language
Oct 22

Adaptive Steering and Remasking for Safe Generation in Diffusion Language Models

The paper introduces an inference‑time defense for Diffusion Language Models that combines adaptive safety steering with safety‑aware remasking. It uses a gating direction to adjust steering strength during denoising and a lightweight response detector to identify unsafe trajectories early, triggering targeted remasking and regeneration under adaptive steering. Experiments on LLaDA and Dream show improved robustness against jailbreak attacks while maintaining benign generation quality.

By Yejin Lee, Ungsik Kim, Yo-Sub Han