Language Model Security Database

Large Language Models (LLMs) are vulnerable to a multi-turn adversarial attack framework termed MEEA (Mere Exposure Effect Attack), which exploits the psychological "mere exposure effect" to bypass safety alignment. Unlike single-turn injections, this vulnerability targets the dynamic nature of LLM safety thresholds during sustained interaction. By subjecting the model to a sequence of optimized, low-toxicity, and semantically progressive prompts, an attacker can induce a gradual shift in the…

Large Language Models (LLMs) are vulnerable to automated, black-box, multi-turn jailbreak attacks coordinated by an adversarial agent trained via Reinforcement Learning (RL). The vulnerability exists because standard safety alignments often optimize for single-turn refusals, failing to account for trajectory-level planning. The attack method, dubbed RL-MTJail, utilizes a multi-turn variant of Group Relative Policy Optimization (GRPO) to train an attacker LLM. This agent optimizes for the…

Large Language Models (LLMs), including GPT-5, Gemini-2.5-Flash, DeepSeek, and Llama-3, are vulnerable to a semantic isomorphism attack known as "Safe2Harm." This vulnerability arises from the failure of safety alignment mechanisms (SFT, RLHF, DPO) to detect harmful underlying principles when they are encapsulated within semantically legitimate scenarios. Attackers can bypass safety filters through a four-stage process: (1) rewriting a harmful query into a safe, principle-equivalent query…

Large Language Model (LLM) agents utilizing the Model Context Protocol (MCP) are vulnerable to semantic injection attacks via adversarial tool descriptors. The vulnerability arises because MCP implementations inject natural language tool metadata (descriptions, schemas) directly into the model's reasoning context without semantic sanitization or cryptographic binding. This allows unprivileged adversaries to register tools containing hidden imperative instructions within the descriptor text…

Reasoning-specialized Large Language Models (LLMs) that utilize Chain-of-Thought (CoT) processes are vulnerable to reasoning-exploitation jailbreaks. Attackers can bypass standard safety alignments (such as RLHF) by using adaptive multi-turn interactions or semantic transformations to induce the model to generate intermediate reasoning steps that "rationalize" or "contextualize" a harmful request. Because current alignment techniques often fail to scale linearly with reasoning depth, forcing…

Large Language Models (LLMs) from multiple vendors are vulnerable to a "poetic jailbreak" attack, a form of stylistic obfuscation where safety guardrails are bypassed by formatting harmful requests as poetry. By encoding prohibited instructions (e.g., malware creation, CBRN protocols) into verse—utilizing metaphors, rhyme schemes, and rhythmic structure—an attacker can evade intent recognition heuristics. The model perceives the input primarily as a creative writing constraint rather than a…

Large Language Models (LLMs) are vulnerable to an automated, self-evolving jailbreak attack framework known as ASTRA (Automated Strategy Discovery, Retrieval, and Evolution). This vulnerability exists because current safety alignment mechanisms (such as RLHF) fail to generalize defenses against dynamically distilled and retrieved attack strategies. ASTRA operates on a closed-loop "attack-evaluate-distill-reuse" mechanism. An attacker LLM generates prompts; a separate strategy extractor…

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…

Large Language Models (LLMs) are vulnerable to a multi-turn jailbreak attack orchestrated by an enhanced Artificial Bee Colony (ABC) algorithm. This vulnerability exists because current safety alignment mechanisms (such as RLHF and DPO) can be bypassed by treating the attack process as a path planning problem on a dynamically weighted graph topology. The ABC algorithm automates the search for adversarial dialogue trajectories by maintaining a population of "bees" (candidate attack paths) that…

A vulnerability, dubbed RoguePrompt, allows for bypassing large language model (LLM) moderation filters by encoding a forbidden instruction into a self-reconstructing payload. The attack uses a dual-layer ciphering process. First, the forbidden prompt is partitioned into two subsequences (e.g., even and odd words). One subsequence is encrypted using a classical cipher like Vigenere, while the other remains plaintext. Both the plaintext subsequence, the Vigenere ciphertext, and natural language…