Prompt Injection Detection

Overview

The field studies how to recognize instructions hidden in ordinary-looking content that could redirect a language model or agent away from the user’s intent. Approaches range from keyword and sparse-text classifiers to fine-tuned models, LLM judges, hidden-state and attention probes, and trajectory analysis that tracks whether an agent’s behavior was actually hijacked. Evaluation spans retrieval-augmented generation, web and tool-using agents, multimodal inputs, and benchmarks testing obfuscation, distribution shift, and harmless text that resembles an attack. A central challenge is balancing attack detection with low false-positive rates and useful task completion, since strong scores on curated benchmarks may not transfer to adaptive attacks or real agent traffic.

Latest papers

CardsList

59 papers10 papers in the last four weeks, level with the four weeks before. 0.1% of all new papers.

  1. MPIDetector: Detecting Multi-modal Prompt Injection via LLM-based Reasoning

    Oct 21, 2026Yiheng Li, Jingyue LiPrompt Injection DetectionMLLM Safety

  2. The Window Is in the Reasoning: When LLM Agents Decide to Follow Prompt Injections

    Oct 16, 2026Haoxuan Jia, Yang Liu, Bin Chong +13Prompt Injection Attacks on AI AgentsPrompt Injection Detection

  3. BrowseSafe++: Benchmarking Prompt Injection Detection Across Web Contexts, Languages, and Browser Views

    Oct 12, 2026Yuetian Chen, Kaiyuan Zhang, Yuntao Du +6Prompt Injection DetectionAI Agent Security Benchmarks

  4. RAG-PIBench: A Leakage-Aware Benchmark for Prompt-Injection Detection in Trustworthy RAG Systems

    Oct 6, 2026Niveen O. Jaffal, Ahmet Yuksel, David MohaisenRAG SecurityPrompt Injection Attacks on LLMs

  5. Passing the Test You Trained On: Re-evaluating Prompt-Injection Detectors for LLM Agents

    Oct 2, 2026Zhuowen LiuPrompt Injection DetectionAI Agent Security Benchmarks

  6. Prompt Injection Detection for Email Agents Through Attack Chain Modeling

    Sep 25, 2026Ahmad Hashmi, Dhyey Patel, Yunting YinPrompt Injection DetectionIndirect Prompt Injection

  7. Decoding Guardrails: XAI-Guided Perturbation Analysis of Prompt Injection Detection

    Sep 21, 2026Fernando Outeda, Gustavo Betarte, Juan Diego Campo +1LLM GuardrailsPrompt Injection Defense

  8. PIDS-Bench: Evaluating Prompt-Injection Detectors Under Over-Defense, Obfuscation, and Distribution Shift

    Sep 14, 2026Yusuf Khalid Shire, Sang-Chul KimDistribution Shift RobustnessPrompt Injection Detection

  9. DriftNet: A Dual-Head Trajectory Transformer for Detecting and Localizing Prompt Injection in LLM Agents

    Sep 9, 2026Asif Pinjari, Mithun Paul Saint-GermainAI Agent Security BenchmarksAI Agent Monitoring

  10. No-Box Vulnerability Analysis: Description-only Detection of Indirect Prompt Injection Vulnerabilities in MCP Servers

    Sep 9, 2026Zehua Zhang, Jie Hu, Pratham Hegde +13MCP SecuritySoftware Vulnerability Detection

  11. AgentDrift: A Step-Labeled Benchmark of Injection-Hijacked LLM Agent Trajectories

    Sep 7, 2026Asif Pinjari, Mithun Paul Saint-GermainAI Agent Security BenchmarksPrompt Injection Attacks on AI Agents

  12. What Guides the Agent? Adjudicating Unauthorized Behavior via Localizing Behavior-Guiding Instructions

    Aug 25, 2026Yichao Gao, Yumo Zhang, Yunhao Yao +4AI Agent SecurityPrompt Injection Attacks on AI Agents

  13. Detecting Contaminated Code-Generation Prompt Batches via Influence Functions

    Aug 14, 2026Francesco Quinzan, Noor Munir, Yishun Lu +1LLM SecurityPrompt Injection Detection

  14. BASIS: Breach-Aware Selective Prompt Injection Shielding with Prefill Attention Probes

    Aug 8, 2026Laiqiao Qin, Tianqing Zhu, Longxiang Gao +1Prompt Injection DefensePrompt Injection Attacks on LLMs

  15. Robust Context-Aware Detection of Malicious Instructions in Text

    Aug 5, 2026Buzhao Liu, Xinhang Ma, Yevgeniy VorobeychikAdversarial TrainingPrompt Injection Defense

  16. Your Agentic LLMs Secretly Encode Latent Signals of Indirect Prompt-Injection Exposure

    Aug 1, 2026Jianshuo Dong, Yiming Liu, Maosen Zhang +6Indirect Prompt InjectionPrompt Injection Defense

  17. When AUC 0.998 Is Not Enough: A Candidate Evaluation Protocol for Hidden-State Probes of Indirect Prompt Injection in Multimodal Computer-Use Agents

    Jun 22, 2026Yanhang Li, Zhichao Fan, Zexin ZhuangAI Agent EvaluationIndirect Prompt Injection

  18. Confidently Wrong: Severity-Aware Calibration of Prompt-Injection Detectors under Attack Shift

    Jun 21, 2026Md Anas BiswasIndirect Prompt InjectionModel Calibration

  19. A Layered Security Framework Against Prompt Injection in RAG-Based Chatbots

    Jun 17, 2026Gulshan Saleem, Nisar Ahmed, Muhammad Imran Zaman +1LLM GuardrailsIndirect Prompt Injection