Language Model Security Database

Large Reasoning Models (LRMs) can be instructed via a single system prompt to act as autonomous adversarial agents. These agents engage in multi-turn persuasive dialogues to systematically bypass the safety mechanisms of target language models. The LRM autonomously plans and executes the attack by initiating a benign conversation and gradually escalating the harmfulness of its requests, thereby circumventing defenses that are not robust to sustained, context-aware persuasive attacks. This…

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…

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.

A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in LLM-enabled agentic systems that execute multi-step plans involving sequential tool calls. The vulnerability arises because plans are not executed atomically. An agent may perform a "check" operation (e.g., reading a file, checking a permission) in one tool call, and a subsequent "use" operation (e.g., writing to the file, performing a privileged action) in another tool call. A temporal gap between these calls, often used for LLM…

Large language models that support a developer role in their API are vulnerable to a jailbreaking attack that leverages malicious developer messages. An attacker can craft a developer message that overrides the model's safety alignment by setting a permissive persona, providing explicit instructions to bypass refusals, and using few-shot examples of harmful query-response pairs. This technique, named D-Attack, is effective on its own. A more advanced variant, DH-CoT, enhances the attack by…

The Magic-Token-Guided Co-Training (MTC) framework for Large Language Models (LLMs) introduces a mechanism where distinct behavioral modes are activated via hardcoded system-level strings known as "magic tokens." A specific vulnerability exists in the implementation of the "negative" (neg) behavior mode, which is explicitly trained to generate unfiltered, risk-prone, and harmful content for internal red-teaming. The framework relies on the secrecy of the magic token (e.g., a random string like…

IntentionReasoner, specifically the 1.5B and 3B parameter versions optimized via Reinforcement Learning (RL), contains a safety regression vulnerability where the RL alignment process degrades the model's resistance to jailbreak attacks compared to the Supervised Fine-Tuning (SFT) baseline. While RL improves general utility and rewriting quality, it inadvertently increases the Attack Success Rate (ASR) for adversarial inputs in smaller architectures. This allows sophisticated jailbreak prompts…

Large Language Models (LLMs) are vulnerable to an adaptive black-box jailbreaking framework named MAJIC (Markovian Adaptive Jailbreaking via Iterative Composition). This vulnerability allows an attacker to bypass safety alignment mechanisms by modeling the selection and composition of prompt disguise strategies as a Markov chain. Unlike static attacks, MAJIC initializes a transition matrix using a proxy model to determine the probability of a specific strategy succeeding after a prior strategy…

A vulnerability exists in the fine-tuning lifecycle of Vision-Language Models (VLMs) derived from open-source base models, termed the "grey-box threat." Adversaries with white-box access to a public base model (e.g., Qwen2-VL) can generate universal adversarial images that successfully bypass safety guardrails in proprietary, fine-tuned downstream variants. This is achieved via the Simulated Ensemble Attack (SEA), which combines two techniques: Fine-tuning Trajectory Simulation (FTS), where…

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…