Language Model Security Database

LLM-as-a-judge systems and automated LLM evaluators are vulnerable to meaning-preserving perturbations, specifically formatting alterations and verbosity manipulations. When grading or classifying text and agentic transcripts, LLM judges exhibit high sensitivity to layout-only changes (such as whitespace and indentation) and response length, frequently altering their scores even when the underlying semantic and factual content remains identical. This allows attackers to bypass automated safety…

Generative reward models deployed as LLM-as-a-Judge (LaaJ) evaluators contain a logic bypass vulnerability where superficial "master key" inputs trigger false positive rewards regardless of actual response quality. Instead of evaluating the candidate's output, large judge models are inadvertently triggered by specific token sequences to solve the prompt independently. This allows malicious actors or policy models undergoing reinforcement learning to consistently game the reward signal by…

Automatic Prefix Caching (APC) in multi-tenant LLM serving systems introduces a timing side-channel vulnerability that permits cross-tenant data leakage. APC shares computed Key-Value (KV) tensors across different users when their requests share identical initial tokens. Because reusing cached tensors is significantly faster than recomputing them, a measurable difference in Time-To-First-Token (TTFT) exists between cache hits and misses. An attacker can exploit this shared cache by sending…

An evasion vulnerability in Text-Attributed Graph (TAG) learning models allows attackers to induce targeted misclassifications via LLM-generated, coordinated perturbations to both graph topology and textual semantics. By identifying a semantically distant "influencer" node, an attacker can use a separate LLM to selectively delete highly relevant edges, insert a deceptive edge connecting the target to the influencer, and slightly modify the target node's text to include a keyword aligned with…

Large Language Models (LLMs) are vulnerable to automated long-tail distribution attacks that exploit their instruction-following and code-execution capabilities to bypass safety alignments. Attackers can obfuscate malicious queries using a semantic-algorithmic representation, embedding the query within reversible encryption-decryption logic (e.g., sequence re-grouping, conditional branching, or index-dependent operations). By providing the model with the encrypted query and the corresponding…

Multi-Modal Large Language Models (MLLMs) are vulnerable to a highly transferable, black-box adversarial image attack known as the Multi-Paradigm Collaborative Attack (MPCAttack). Attackers can craft imperceptible visual perturbations by jointly aggregating and optimizing semantic feature representations extracted from surrogate models across three distinct learning paradigms: cross-modal alignment (e.g., CLIP), multi-modal understanding (e.g., InternVL3), and visual self-supervised learning…

A vulnerability in Multimodal Large Language Models (MLLMs) allows attackers to bypass safety alignments via Multi-Image Dispersion and Semantic Reconstruction (MIDAS). Attackers decompose malicious instructions into risk-bearing semantic subunits, fragment them, and distribute them across multiple benign-looking Game-style Visual Reasoning (GVR) puzzles (e.g., Letter Equations, Rank-and-Read, Odd-One-Out). A sanitized, persona-driven textual prompt with sequential placeholders is then used to…

Large Vision-Language Models (LVLMs) are vulnerable to multi-turn, multi-modal jailbreak attacks where malicious intent is incrementally introduced and obfuscated through intertwined text and image prompts. Attackers can systematically bypass safety alignments by starting with self-optimized, benign-seeming conversation starters (horizontal expansion) and progressively stacking text and image attack augmentations across multiple conversation turns (vertical expansion). Furthermore, models fail…

A vulnerability in Large Language Models (LLMs) equipped with built-in "thinking" or step-by-step reasoning modes allows attackers to bypass safety alignments, trigger reasoning collapse, and cause resource exhaustion. The vulnerability is exploited via a Multi-Stream Perturbation Attack, which fragments the sequential integrity of a harmful prompt by word-by-word interleaving it with benign auxiliary tasks (e.g., "Explain the water cycle"). By wrapping the benign text streams in specific…

Claude Opus 4.6, Gemini 3.1 Pro, and GPT-5.2 are vulnerable to safety guardrail bypasses via authoritative and operational contextual framing. Attackers can evade safety classifiers by encapsulating restricted objectives (e.g., malicious code generation, misinformation, social engineering) within "legitimate" professional contexts, such as graduate-level academic research, network stress-testing, or corporate security awareness simulations. This vulnerability is exploitable both via zero-shot…