Skip to main content
LLM Security Database
Skip to research search
Updated 7/21/2026, database is current

Language Model Security Database

959 research findings · 1077 evaluated models

Filtered research findings

43 entries

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

The paper presents SkillSec-Eval, a controlled evaluation of attacks against reusable agent skills across repository admission, semantic retrieval, planner selection, runtime execution, and updates. It reports that malicious metadata, retrieval manipulation, unsafe workflow composition, and poisoned updates can cause agents to retrieve, select, or execute unintended skills. These are paper-reported benchmark results, not independently verified vulnerabilities in a named production product.

Agent Skill Security: Threat Models, Attacks, Defenses, and Evaluation
Affects: all-MiniLM-L6-v2, Gemini 3.1 Pro, Gemini 1.5 Flash

Source: arXiv

The paper describes GhostWriter, a reproducible two-phase attack against tool-using agents with persistent memory: untrusted email or calendar content is admitted into long-term memory, then later retrieved during a benign user task and treated as trusted context. In the authors’ controlled evaluation, this could steer subsequent agent actions despite the adversary lacking direct access to the agent, memory store, account, or later prompt. The paper reports an average 98% memory-injection rate…

When Agents Remember Too Much: Memory Poisoning Attacks on Large Language Model Agents
Affects: GPT-5.4-mini, DeepSeek V4 Flash, Gemini 2.5 Flash +1 more

Source: arXiv

The paper describes a reproducible agent-memory poisoning issue: untrusted content stored in persistent memory can later influence consequential actions after its origin is laundered through agent summarization, trusted-tool echo, or manufactured corroboration. The paper reports that content scoring, lineage, and single-session capability/IFC defenses remain vulnerable because they decide authority from malleable content or derivation signals. This is a paper-reported evaluation; it was not…

Securing LLM-Agent Long-Term Memory Against Poisoning: Non-Malleable, Origin-Bound Authority with Machine-Checked Guarantees
Affects: GPT-5 Chat, GPT-4o Mini, Claude Opus 4.1 +5 more

Source: arXiv

The paper describes and evaluates a reproducible application-layer weakness in agents with persistent memory: untrusted external content can cross the memory-write boundary, be stored as trusted factual, experience, or procedural memory, and influence later sessions. It identifies four write channels—explicit writes, policy-driven writes, compaction, and experience-to-procedure synthesis—and six attack classes. For safe defensive testing, use MPBench’s two-phase structure in an isolated agent…

From Untrusted Input to Trusted Memory: A Systematic Study of Memory Poisoning Attacks in LLM Agents
Affects: GPT-oss 120B

Source: arXiv

The paper presents a specific black-box indirect prompt-injection evaluation: attacker-controlled external content can cause a memory-enabled assistant or external memory manager to persist a fabricated user memory, which may later be retrieved in a separate session and steer responses or agent actions. The authors evaluate injection, retrieval, and conditional adversarial usage separately across synthetic document and future-session datasets. The released repository provides defensive…

Hidden in Memory: Sleeper Memory Poisoning in LLM Agents
Affects: GPT-5.4, GPT-5.5, Claude Sonnet 4.6 +3 more

Source: arXiv

A vulnerability exists in multi-user LLM agents utilizing persistent shared state, allowing Unintentional Cross-User Contamination (UCC). Without requiring any malicious input or attacker, benign user interactions containing locally valid scope constraints, formatting preferences, or procedural rules are persisted into the agent's shared memory or conversational context. The agent subsequently retrieves and misapplies these scope-bound artifacts to unrelated tasks from different users. This…

No Attacker Needed: Unintentional Cross-User Contamination in Shared-State LLM Agents
Affects: GPT-4o

Source: arXiv

Updated 4/10/2026

A supply-chain vulnerability in LLM-mediated robotic control systems allows attackers to execute unauthorized physical actions via structured backdoor attacks embedded in LoRA adapters. By poisoning the fine-tuning dataset to map specific natural-language trigger phrases directly to malicious, syntactically valid JSON control commands (structured-output poisoning), the backdoor bypasses natural-language reasoning layers and propagates deterministically to downstream robotic middleware (e.g…

From Prompt to Physical Action: Structured Backdoor Attacks on LLM-Mediated Robotic Control Systems
Affects: Llama 3.1 8B Instruct, Gemma 2 9B IT, DeepSeek R1 Distill Llama 8B +2 more

Source: arXiv

An implicit reasoning hijacking vulnerability exists in Retrieval-Augmented Generation (RAG) and LLM-based agent frameworks. Attackers with write access to an agent's external memory or knowledge base can inject adversarially optimized malicious instances that trigger jailbreaks without requiring any modifications to the user's input prompt. The attack utilizes a shadow model to extract high-contribution subword tokens from anticipated benign user queries via log-probability changes and…

Stop Fixating on Prompts: Reasoning Hijacking and Constraint Tightening for Red-Teaming LLM Agents
Affects: GPT-3.5 Turbo, GPT-4o, GPT-5 +4 more

Source: arXiv

Memory-augmented LLM web agents utilizing raw trajectory memory are vulnerable to Environment-injected Trajectory-based Agent Memory Poisoning (eTAMP). Attackers can embed malicious instructions within user-generated web content (e.g., product pages, forum posts). When the agent processes this content during a routine task, the instructions are passively ingested into its raw trajectory memory. During subsequent, entirely separate tasks on different websites, semantic retrieval mechanisms pull…

Poison Once, Exploit Forever: Environment-Injected Memory Poisoning Attacks on Web Agents
Affects: GPT-4o, GPT-5, Qwen 2.5 72B

Source: arXiv

The paper presents a controlled, reproducible evaluation in which untrusted MCP tool descriptions contain hidden instructions that attempt to induce coding agents to access files, invoke other tools, create deceptive links, or execute remote scripts. The authors report that several clients accepted poisoned metadata without adequate validation or parameter visibility; Cursor 1.6.45 was reported unsafe across all four tested vectors. These are paper-reported results from isolated local tests…

Are AI-assisted Development Tools Immune to Prompt Injection?
Affects: Claude Sonnet 4.5, Grok Code Fast 1, Gemini 2.5 Pro +1 more

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.