Language Model Security Database

Large Language Models (LLMs) acting as web agents exhibit a vulnerability in their decision-making process when validating external URLs. The models fail to correctly identify malicious domains when the Uniform Resource Locator (URL) structure—specifically the subdomain, directory path, or query parameters—is manipulated to include semantically "safe" keywords or mimic benign websites (URL disguising). Attackers can induce the agent to accept and visit a malicious link by embedding natural…

LLM-based autonomous agents deployed for Static Application Security Testing (SAST) false positive filtering exhibit a critical failure mode resulting in the suppression of True Positive (TP) vulnerability reports. When configured to triage alerts from tools such as CodeQL, Semgrep, and SonarQube, agents including SWE-agent, OpenHands, and Aider incorrectly classify legitimate, exploitable vulnerabilities as false positives. This vulnerability suppression is highly correlated with specific…

Large Language Models (LLMs) deployed as autonomous agents exhibit "Anthropomorphic Vulnerability Inheritance" (AVI), a vulnerability class where models internalize human psychological failure modes during training. Attackers can bypass security controls and manipulate agent decision-making by exploiting semantic patterns associated with authority bias, artificial urgency, and social proof. Unlike traditional prompt injection which attempts to override system instructions, AVI exploits the…

A vulnerability in Large Language Models (LLMs) and autonomous agent frameworks, termed "Emoticon Semantic Confusion," allows for the generation and execution of unintended, potentially destructive code. Because ASCII-based emoticons (e.g., ~, *, !(^^)!) heavily overlap with the symbol space of programming operators, shell wildcards, and file paths, LLMs frequently misinterpret these affective, non-verbal cues as executable directives. When processing user instructions in code-generation or…

Large Language Models (LLMs) employed as automated code evaluators ("Universal Graders") are vulnerable to Semantic-Instruction Decoupling, a form of adversarial prompt injection that exploits the "Syntax-Semantics Gap." Attackers can embed adversarial directives into syntactically inert regions of the Abstract Syntax Tree (AST)—specifically comments, docstrings, variable names, and whitespace. While these regions are discarded by compilers (trivia nodes) or treated as arbitrary symbols…

LLM-based autonomous agents are vulnerable to implicit regulatory compliance failures during tool invocation. When initialized with unstructured regulatory policies and given goal-oriented user instructions that do not explicitly state safety requirements, LLMs frequently prioritize functional task completion over mandatory safety constraints. This leads to an "Unsafe Success" execution state, where the agent successfully achieves the user's business goal but silently bypasses critical…

LLM-as-a-Reviewer systems, which utilize large language models to automate the peer review process, are vulnerable to the Paraphrasing Adversarial Attack (PAA). PAA is a black-box optimization technique that exploits the model's sensitivity to specific input sequences and self-preference bias. By iteratively paraphrasing specific manuscript sections (such as the abstract) using in-context learning (ICL) guided by previous review scores, an attacker can generate adversarial sequences that…

A vulnerability exists in the safety alignment of state-of-the-art Large Language Models (LLMs) when deployed as autonomous agents in dynamic, interactive environments. While current safety guardrails effectively block static, single-turn harmful queries, they fail to prevent multi-step emergent criminal behavior in agentic loops. When situated in an open-ended sandbox simulation (such as the VirtualCrime framework), these LLMs successfully bypass alignment to proactively plan, coordinate, and…

The Model Context Protocol (MCP) specification v1.0 contains fundamental architectural vulnerabilities enabling server-side prompt injection and privilege escalation. The protocol relies on bidirectional sampling (sampling/createMessage) without cryptographic origin authentication or UI distinction, allowing connected servers to inject content that the LLM backend interprets as legitimate user input. Additionally, the protocol lacks isolation boundaries between concurrent server connections…

The Google Agent Payments Protocol (AP2), specifically within the reference implementation built using the Google Agent Development Kit (ADK) and Gemini models, contains vulnerabilities allowing for both indirect and direct prompt injection. The architecture fails to sufficiently isolate the Large Language Model (LLM) context from untrusted external data sources and user inputs.