Language Model Security Database

Implementations of Large Language Model (LLM) watermarking algorithms—specifically KGW (Kirchenbauer et al.), Semantic Invariant Robust (SIR) Watermark, Entropy-based Text Watermarking (EWD), and Unbiased Watermarking—are vulnerable to watermark stripping via adversarial text perturbation. When watermarked text generated by models such as OPT-1.3B is subjected to automated paraphrasing or back-translation (e.g., English $\to$ French $\to$ English), the embedded statistical signals are…

Multimodal Large Language Models (MLLMs) are vulnerable to a jailbreak attack strategy known as Balanced Structural Decomposition (BSD). This vulnerability exploits a structural trade-off in safety alignment where models fail to detect malicious intent when the input balances semantic relevance ("On-Topicness") with distributional novelty ("OOD-Intensity"). The attack functions by recursively decomposing a harmful text objective into a tree of sub-tasks using an "Explore" (diversity) and…

Multi-tenant Large Language Model (LLM) inference systems utilizing global Key-Value (KV) cache sharing are vulnerable to a timing side-channel attack. By measuring the Time-To-First-Token (TTFT) latency of crafted API requests, an unprivileged remote attacker can determine if specific token sequences have been previously processed and cached by the system for other users. This observable timing difference between cache hits (low TTFT) and cache misses (high TTFT) allows for the token-by-token…

Large Language Models (LLMs) implementing "Thinking Mode" (also known as Reasoning Mode or Chain-of-Thought) exhibit a heightened susceptibility to jailbreak attacks compared to their non-reasoning counterparts. When a model is prompted to reason step-by-step (often delimited by specific tokens like <think> and </think>), the internal reasoning process frequently overrides safety alignment training. Research indicates that during the generation of the thinking chain, the model often…

Large Language Models (LLMs) are vulnerable to automated adversarial attacks that systematically combine multiple jailbreaking "primitives" into complex prompt chains. A dynamic optimization engine can generate and test billions of unique combinations of techniques (e.g., low-resource language translation, payload splitting, role-playing) to bypass safety guardrails. This combinatorial approach differs from manual red-teaming by systematically exploring the attack surface, achieving…

A vulnerability, known as Latent Fusion Jailbreak (LFJ), exists in certain Large Language Models that allows an attacker with white-box access to bypass safety alignments. The attack interpolates the internal hidden state representations of a harmful query and a thematically similar benign query. By using gradient-guided optimization to identify and modify influential layers and tokens, a fused hidden state is created that causes the model to generate prohibited content in response to the…

Multimodal Large Language Models (MLLMs) employed in autonomous driving (AD) systems are vulnerable to a physically realizable adversarial patch attack dubbed "PhysPatch." This vulnerability exists because MLLMs inherit susceptibility to visual adversarial perturbations from their vision backbones. The attack utilizes a semantic-aware mask initialization strategy combined with a potential field algorithm to identify physically plausible regions for patch placement within a driving scene (e.g…

A vulnerability exists in the graph encoding architecture of LLaGA (Large Language and Graph Assistant), specifically within the "neighborhood detail template" used to construct node sequences. LLaGA enforces a fixed-shape computational tree for each node; when a target node has fewer neighbors than the required template size (e.g., $k$ children), the system utilizes placeholders to maintain the fixed structure.

Audio-Language Models (ALMs) including Qwen2.5-Omni (3B and 7B) and Phi-4-Multimodal are vulnerable to "WhisperInject," a two-stage adversarial audio attack that bypasses safety guardrails. The vulnerability allows an attacker to inject imperceptible perturbations into benign audio inputs (e.g., a query about the weather) that force the model to generate specific harmful content. The attack utilizes a novel optimization method, Reinforcement Learning with Projected Gradient Descent (RL-PGD)…

A vulnerability exists in LLM-based Multi-Agent Systems (LLM-MAS) where an attacker with control over the communication network can perform a multi-round, adaptive, and stealthy message tampering attack. By intercepting and subtly modifying inter-agent messages over multiple conversational turns, an attacker can manipulate the system's collective reasoning process. The attack (named MAST in the reference paper) uses a fine-tuned policy model to generate a sequence of small, context-aware…