Skip to main content
LLM Security Database
Skip to research search
Last analyzed 9/9/2026

Language Model Security Database

985 research findings · 1123 evaluated models

Filtered research findings

55 entries

Matches every word across titles, descriptions, sources, affected systems, and models.

Published 1/1/2026
Analyzed 2/22/2026

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…

Breaking the Protocol: Security Analysis of the Model Context Protocol Specification and Prompt Injection Vulnerabilities in Tool-Integrated LLM Agents
Evaluated models: GPT-4o, Claude 3.5 Sonnet, Llama 3.1 70B

Source: arXiv

Published 12/1/2025
Analyzed 12/8/2025

A vulnerability exists in OpenAI's Custom GPTs platform where the lack of effective isolation between the system context ("Expert Prompt"), external knowledge retrieval, and user input allows for unauthorized information disclosure and tool misuse. By employing specific prompt injection techniques—including Hex injection, Many-shot prefix attacks, and Knowledge Poisoning (uploading malicious files)—an attacker can bypass safety guardrails. This results in the extraction of proprietary system…

An Empirical Study on the Security Vulnerabilities of GPTs
Evaluated models: DALL-E

Source: arXiv

Published 12/1/2025
Analyzed 2/21/2026

A vulnerability exists in MetaGPT's DataInterpreter agent (and similar RAG-based agents utilizing persistent long-term memory) that allows for persistent memory poisoning via indirect injection. The vulnerability exploits the agent's "semantic imitation heuristic," where the agent blindly trusts and imitates retrieved past experiences. An attacker can supply a benign-looking artifact (e.g., a README file or documentation) containing executable code blocks or structured text that the agent…

MemoryGraft: Persistent compromise of LLM agents via poisoned experience retrieval
Evaluated models: GPT-4o

Source: arXiv

Published 10/1/2025
Analyzed 10/31/2025

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…

Collaborative Shadows: Distributed Backdoor Attacks in LLM-Based Multi-Agent Systems
Evaluated models: Gemini 2.5 Pro, GLM 4.5, GPT-4.1 +2 more

Source: arXiv

Published 10/1/2025
Analyzed 1/14/2026

Large Language Model (LLM) agents utilizing long-term memory or Retrieval-Augmented Generation (RAG) are vulnerable to context-dependent memory injection attacks. Unlike traditional prompt injections that are overtly malicious, this vulnerability involves injecting records that appear benign and coherent in isolation—thereby bypassing standard perplexity filters and static content moderation (e.g., LlamaGuard). These records contain "sleeping" malicious logic that is only activated when…

A-memguard: A proactive defense framework for llm-based agent memory
Evaluated models: GPT-4o, Llama 3.1 8B

Source: arXiv

Published 9/1/2025
Analyzed 12/9/2025

Retrieval-Augmented Generation (RAG) systems in the health domain are vulnerable to corpus poisoning attacks where adversarial documents—specifically those generated via "Liar" (fabricated from scratch based on an incorrect stance) and "Few-Shot Adversarial Prompting" (FSAP)—are injected into the retrieval pool. When these adversarial documents are retrieved and presented as context, they successfully override the Large Language Model's (LLM) internal safety alignment and ground-truth…

Evaluating the Robustness of Retrieval-Augmented Generation to Adversarial Evidence in the Health Domain
Evaluated models: GPT-4.1, GPT-5, Claude 3.5 Haiku +3 more

Source: arXiv

Published 9/1/2025
Analyzed 12/8/2025

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…

Breaking to Build: A Threat Model of Prompt-Based Attacks for Securing LLMs
Evaluated models: Not reported

Source: arXiv

Published 8/1/2025
Analyzed 12/9/2025

A vulnerability exists in the graph encoding architecture of LLaGA (Large Language and Graph Assistant), specifically within the "neighborhood detail template" used to construct node sequences. LLaGA enforces a fixed-shape computational tree for each node; when a target node has fewer neighbors than the required template size (e.g., $k$ children), the system utilizes placeholders to maintain the fixed structure.

Adversarial Attacks and Defenses on Graph-aware Large Language Models (LLMs)
Evaluated models: GPT-4, Llama 2 7B, Vicuna 7B

Source: arXiv

Published 7/1/2025
Analyzed 12/30/2025

A remote code execution (RCE) and privilege escalation vulnerability exists in Large Language Model (LLM) multi-agent systems and agentic RAG (Retrieval-Augmented Generation) architectures. The vulnerability arises from "Inter-Agent Trust Exploitation," where LLM agents implicitly trust instructions received from peer agents, bypassing safety guardrails and jailbreak defenses that are active during direct human-to-LLM interaction. An attacker can inject a malicious command payload (e.g., a…

The Dark Side of LLMs: Agent-based Attack Vectors for System-level Compromise
Evaluated models: GPT-4o Mini, GPT-4o, GPT-4.1 Mini +15 more

Source: arXiv

Published 6/1/2025
Analyzed 6/30/2025

A vulnerability in fine-tuning-based large language model (LLM) unlearning allows malicious actors to craft manipulated forgetting requests. By subtly increasing the frequency of common benign tokens within the forgetting data, the attacker can cause the unlearned model to exhibit unintended unlearning behaviors when these benign tokens appear in normal user prompts, leading to a degradation of model utility for legitimate users. This occurs because existing unlearning methods fail to…

Keeping an eye on llm unlearning: The hidden risk and remedy
Evaluated models: Llama 3.1 8B, Mistral 7B v0.3

Source: arXiv

Research methodology

Entries summarize publicly available primary-source security research. Model names reflect only systems explicitly evaluated by the cited paper, and measurements are research-reported unless independent verification is stated.