Language Model Security Database

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…

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) from multiple vendors exhibit vulnerabilities to jailbreaking techniques that bypass safety guardrails, enabling the automated generation of highly persuasive phishing content specifically targeted at elderly victims. By employing "Roleplay Authority" (posing as researchers) or "Safety Turned Off" (explicit meta-instructions) prompting strategies, attackers can coerce the models into producing social engineering emails—such as fake government benefit notifications…

A black-box guardrail reverse-engineering vulnerability exists in Large Language Model (LLM) serving systems that employ output filtering mechanisms. The vulnerability allows remote attackers to replicate the proprietary decision-making policy and rule sets of the target's safety guardrail without direct access to model parameters. This is achieved through a technique termed Guardrail Reverse-engineering Attack (GRA), which utilizes a reinforcement learning framework combined with genetic…

Multiple open-weight Large Language Models (LLMs)—specifically those prioritizing capability over safety alignment—exhibit a critical vulnerability to adaptive multi-turn prompt injection and jailbreak attacks. While these models effectively reject isolated, single-turn adversarial inputs (averaging ~13.11% Attack Success Rate), they fail to maintain safety guardrails and policy enforcement across extended conversational contexts. By leveraging iterative strategies such as "Crescendo" (gradual…

Mobile LLM-based agents (including Mobile-Agent-E, AppAgent, AutoDroid, and others) are vulnerable to indirect prompt injection attacks delivered via untrusted third-party mobile channels, such as in-app advertisements, system notifications, and embedded webviews. These agents utilize Multimodal Large Language Models (MLLMs) to perceive the device state via screenshots or accessibility trees. The vulnerability exists because the agents concatenate the user's prompt ($p$) with the environmental…

LLM-based coding agents integrated into IDEs (e.g., VS Code Copilot, Cursor, Windsurf) are vulnerable to a query-agnostic Indirect Prompt Injection (IPI) attack termed "QueryIPI." This vulnerability allows an attacker to achieve Remote Code Execution (RCE) on the developer's machine by injecting a malicious tool definition (e.g., via the Model Context Protocol) into the agent's context.

A vulnerability exists in the self-reflection and introspection capabilities of Large Language Models (LLMs) and Vision-LLMs that allows attackers to perform black-box adversarial optimization using only textual model responses. This technique, termed "Asking for Directions" (AfD), bypasses the need for access to gradients, logits, or continuous confidence scores. The attacker employs a hill-climbing optimization strategy where they present the target model with two candidate inputs (an…

Agentic AI browsers and LLM-powered browser extensions are vulnerable to indirect prompt injection via the processing of untrusted web content. The vulnerability arises when the AI agent ingests the Document Object Model (DOM), including hidden elements, HTML comments, metadata, and accessibility labels, into its context window to perform tasks such as page summarization or autonomous navigation. Because the LLM cannot distinguish between system instructions and untrusted external data, an…

A distributed backdoor vulnerability, named "Collaborative Shadows", exists in LLM-based Multi-Agent Systems (MAS) that rely on external or modifiable tools. An attacker can poison multiple agent tools by embedding inert, encrypted "attack primitives" within them. These primitives are fragments of a larger malicious payload. A carefully crafted user instruction acts as both a trigger and a decryption key. The instruction steers the agents to collaborate in a specific sequence, causing them to…