Jailbreaking LLMs & VLMs: Mechanisms, Evaluation, and Unified Defense
Zejian Chen 1, Chao Li 1, Xi Zhang 1, Litian Zhang 1, He YiMin 2
1 Beijing University of Posts and Telecommunications
2 China Academy of Information and Communications Technology
Published on arXiv
2601.03594
Input Manipulation Attack
OWASP ML Top 10 — ML01
Prompt Injection
OWASP LLM Top 10 — LLM01
Key Finding
Proposes a unified three-layer defense framework (perception, generation, parameter) consolidating shared jailbreak defense mechanisms across LLMs and VLMs in both text-only and multimodal settings.
This paper provides a systematic survey of jailbreak attacks and defenses on Large Language Models (LLMs) and Vision-Language Models (VLMs), emphasizing that jailbreak vulnerabilities stem from structural factors such as incomplete training data, linguistic ambiguity, and generative uncertainty. It further differentiates between hallucinations and jailbreaks in terms of intent and triggering mechanisms. We propose a three-dimensional survey framework: (1) Attack dimension-including template/encoding-based, in-context learning manipulation, reinforcement/adversarial learning, LLM-assisted and fine-tuned attacks, as well as prompt- and image-level perturbations and agent-based transfer in VLMs; (2) Defense dimension-encompassing prompt-level obfuscation, output evaluation, and model-level alignment or fine-tuning; and (3) Evaluation dimension-covering metrics such as Attack Success Rate (ASR), toxicity score, query/time cost, and multimodal Clean Accuracy and Attribute Success Rate. Compared with prior works, this survey spans the full spectrum from text-only to multimodal settings, consolidating shared mechanisms and proposing unified defense principles: variant-consistency and gradient-sensitivity detection at the perception layer, safety-aware decoding and output review at the generation layer, and adversarially augmented preference alignment at the parameter layer. Additionally, we summarize existing multimodal safety benchmarks and discuss future directions, including automated red teaming, cross-modal collaborative defense, and standardized evaluation.
Key Contributions
- Three-dimensional survey framework spanning attack methods, defense strategies, and evaluation metrics across text-only LLMs and multimodal VLMs
- Unified defense principles organized across perception layer (variant-consistency and gradient-sensitivity detection), generation layer (safety-aware decoding and output review), and parameter layer (adversarially augmented preference alignment)
- Differentiation between hallucinations and jailbreaks by intent and triggering mechanism, with coverage of multimodal safety benchmarks and future directions including automated red teaming and standardized evaluation
🛡️ Threat Analysis
The survey explicitly covers image-level adversarial perturbations and gradient/adversarial learning attacks targeting VLMs — visual adversarial inputs that manipulate VLM outputs qualify as ML01 input manipulation attacks.