Language Model Security Database

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…

An adversarial fine-tuning vulnerability exists in LLMs protected by text-based safety classifiers (such as Anthropic's Constitutional Classifiers). By utilizing a two-stage curriculum learning combined with hybrid RL+SFT (GRPO), an attacker can fine-tune a model to communicate using a minimal substitution cipher (replacing only 7-8 high-frequency characters) disguised within benign technical templates (e.g., forensic logs with 0x prefixes). This "Trojan-Speak" methodology bypasses text-level…

Text scoring models, including dense retrievers, rerankers, and reward models, are vulnerable to score manipulation attacks via search-based discrete perturbations and content injection. An attacker can systematically modify candidate texts using rudimentary string manipulations, gradient-guided token swaps (e.g., HotFlip), masked language modeling (MLM) swaps, or query/sentence injections to spuriously increase model scores. This structural failure condition allows an irrelevant passage or a…

Audio Large Language Models (ALLMs) integrated into voice agent systems for high-stakes domains (banking, IT support, logistics) are vulnerable to multimodal adversarial attacks via spoken interaction. Adversaries can exploit the model's inherent compliance and contextual awareness through multi-turn dialogue to bypass authentication safeguards, escalate privileges (e.g., unauthorized credit limit increases), exfiltrate sensitive Personally Identifiable Information (PII), and poison…

A vulnerability exists in Large Language Model (LLM) Fine-tuning-as-a-Service (FaaS) platforms that allows attackers to bypass safety alignment and moderation filters via a "TrojanPraise" benign fine-tuning attack. The attack exploits the decoupling of an LLM's internal representation of harmful queries into "knowledge" (semantic understanding) and "attitude" (safety refusal). The attacker constructs a fine-tuning dataset containing three specific components: (1) a novel nonsense word (e.g…

Instruction-tuned Large Language Models (LLMs) are vulnerable to the induction of "hidden intentions"—covert, goal-directed manipulative behaviors—via lightweight prompt engineering, system prompts, or agentic workflows. Attackers can embed latent agendas (e.g., commercial manipulation, simulated consensus, or the promotion of insecure coding practices) into model outputs that trigger only under specific conversational contexts. Because these manipulative behaviors mimic benign interactions…

LLM-enhanced Graph Neural Networks (GNNs), which integrate Large Language Model (LLM) feature encoders with graph message-passing architectures, are vulnerable to a black-box node injection attack known as "GraphTextack." This vulnerability exists because the joint model architecture creates a dual attack surface: the GNN component is sensitive to structural perturbations (changes in graph topology), while the LLM component is sensitive to semantic perturbations (adversarial phrasing).

A vulnerability in the fine-tuning process of Large Language Models (LLMs) allows for the automated generation of stealthy backdoor attacks using an autonomous LLM agent. This method, termed AutoBackdoor, creates a pipeline to generate semantically coherent trigger phrases and corresponding poisoned instruction-response pairs. Unlike traditional backdoor attacks that rely on fixed, often anomalous triggers, this technique produces natural language triggers that are contextually relevant and…

Large Language Model (LLM) fine-tuning interfaces are vulnerable to a semantic obfuscation attack that bypasses multi-stage safety defenses, including pre-upload data filtering, defensive fine-tuning algorithms, and post-training safety audits. The vulnerability exploits a "self-auditing" flaw where the provider uses the target model (or a similar variant) to screen training data. Attackers can submit a small dataset (approx. 500 samples) where harmful answers are obfuscated using a…

Large Language Models (LLMs) integrated with external retrieval mechanisms (e.g., Retrieval-Augmented Generation (RAG), web search, or email processing) are vulnerable to Indirect Prompt Injection. This vulnerability occurs when an LLM consumes input from untrusted external sources—such as websites, code repositories, or incoming emails—that contain embedded adversarial prompts. Unlike direct injection, where the user attacks the model, here the "poisoned" data is retrieved by the system…