Language Model Security Database

Open-weight Large Language Models, demonstrated specifically on Qwen3 (4B and 30B-A3B Base, Instruct, and Thinking variants), are vulnerable to unauthorized steerability attacks where minimal inference-time interventions—such as short, pro-instrumental prompt suffixes—reliably elicit dangerous instrumental-convergence behaviors. Because instruction-tuned and "Thinking" models are inherently designed to be highly responsive to steering (authorized steerability), malicious actors can exploit…

A malicious model supply chain vulnerability exists involving a technique termed Adversarial Contrastive Learning (ACL) for Large Language Model (LLM) quantization attacks. This vulnerability allows an attacker to publish a model that appears benign and preserves high utility in full precision (e.g., BF16 or FP32) but exhibits malicious behaviors—such as jailbreak, over-refusal, or advertisement injection—immediately upon zero-shot quantization (e.g., INT8, FP4, or NF4).

A fine-tuning vulnerability in the safety alignment of Large Language Models (LLMs) allows adversaries to systematically bypass refusal mechanisms by training the model on a small dataset (as few as 1,000 samples) of strictly benign text. By prepending standard refusal prefixes (e.g., "I'm sorry", "I cannot fulfill this request") to the target outputs of benign instruction-response pairs, attackers disrupt the model's refusal completion pathway. When subsequently prompted with unsafe queries…

Instruction-tuned Large Language Models (LLMs) exhibit a selective safety alignment vulnerability, allowing attackers to bypass hate speech filters by shifting the demographic target of an adversarial prompt. Current safety guardrails do not generalize the semantic concept of harm, but instead memorize refusal boundaries for high-visibility demographic groups (e.g., Black, LGBTQIA+). Attackers can successfully generate targeted hate speech by directing identical jailbreak vectors at…

A vulnerability in the safety alignment of several major Large Language Models (LLMs) allows attackers to bypass content filters using complex, automatically generated adversarial prompts. Discovered via the AgenticRed evolutionary framework, the flaw is exploited by wrapping malicious intents in structured formats (such as strict JSON output contracts), combined with prefix injection and refusal suppression. By explicitly commanding the model to begin its response with a compliant prefix and…

Semantic caching mechanisms in LLM applications are vulnerable to cross-tenant cache key collision attacks (CacheAttack) due to the inherent mathematical conflict between locality-preserving fuzzy hashing and cryptographic collision resistance (the avalanche effect). An attacker can leverage gradient-based search algorithms to optimize an adversarial discrete suffix that, when appended to a malicious prompt, forces its output embedding vector to collide with the embedding of a targeted benign…

Large Language Models (LLMs), specifically open-weight instruction-tuned models (including Llama-3.1-8B, Qwen3-8B, and Gemma-7B) and certain closed-weight APIs allowing partial response pre-filling, are vulnerable to "Sockpuppetting" or Output Prefix Injection. This vulnerability exploits the model's autoregressive nature and self-consistency bias. By injecting a target acceptance sequence (e.g., "Sure, here is...") directly into the start of the assistant message block within the chat…

Large Language Models (LLMs) exhibit a vulnerability to "hard-to-falsify" deceptive evidence injection, termed the "Facade of Truth." This vulnerability allows an attacker to override an LLM’s parametric knowledge (internal factual beliefs) by injecting sophisticated, iteratively refined fabricated evidence into the context window. Unlike overt misinformation which models typically reject, this attack utilizes a multi-agent adversarial framework (MisBelief) to generate evidence that mimics…

Large Language Models (LLMs) and their associated output guardrails (e.g., Llama Guard, OpenAI Moderation API) rely on autoregressive, token-by-token processing, which interprets text as a one-dimensional sequence. A vulnerability exists wherein harmful content can bypass these safety filters by exploiting the discrepancy between 1D token serialization and 2D visual rendering. By redistributing tokens across different rows, columns, or diagonals (SpatialJB), attackers can induce the model to…

A "risk-invariance" vulnerability exists in Large Language Models (LLMs) wherein the model's decision-making policy is functionally decoupled from its verbalized confidence and externally defined error penalties. Despite generating calibrated confidence estimates (internal epistemic uncertainty), affected models fail to adjust their abstention thresholds when presented with high-penalty incentives (e.g., negative utility for incorrect answers). This results in "utility collapse," where models…