{
  "slug": "big-sleep",
  "name": "Big Sleep and CodeMender",
  "tagline": "Google's LLM bug hunter and its patching companion",
  "maintainer": "Google DeepMind and Project Zero",
  "url": "https://blog.google/innovation-and-ai/technology/safety-security/cybersecurity-updates-summer-2025/",
  "category": "frontier",
  "targets": [
    "C / C++ open source",
    "V8",
    "SQLite",
    "FFmpeg"
  ],
  "approach": "LLM agent evolved from Project Naptime; CodeMender validates with sandboxed PoCs and patches with a model-as-judge; Gemini 3.5 Flash Cyber trained on OSV and OSS-Fuzz data",
  "license": "Big Sleep internal; CodeMender preview on Google Cloud; Flash Cyber gated to governments and partners",
  "status": "Active",
  "since": "2024 (Naptime)",
  "summary": "Big Sleep is Google's LLM-based bug hunter, credited with 20 flaws in FFmpeg and ImageMagick in August 2025 and with catching SQLite CVE-2025-6965 before exploitation. CodeMender (preview) validates and patches, and Gemini 3.5 Flash Cyber (July 2026) found 55 confirmed V8 issues. None is sold as a product to the public.",
  "details": [
    "Google's work is the strongest evidence that frontier models find real memory-safety bugs in widely used C code. Access is the constraint: Big Sleep is internal and Flash Cyber is gated."
  ],
  "strengths": [
    "Pre-exploitation catch in SQLite.",
    "Rigorous Project Zero disclosure.",
    "CodeMender closes the loop to patches."
  ],
  "limits": [
    "Not available as a service.",
    "C and C++ focus.",
    "Not cryptography-aware."
  ],
  "fit": [
    "Track its findings in your dependencies; you cannot run it yourself."
  ],
  "references": [
    [
      "Google cybersecurity updates (2025-08)",
      "https://blog.google/innovation-and-ai/technology/safety-security/cybersecurity-updates-summer-2025/"
    ],
    [
      "CodeMender",
      "https://cloud.google.com/security/codemender"
    ],
    [
      "Gemini 3.5 Flash Cyber (2026-07-21)",
      "https://deepmind.google/blog/introducing-gemini-3-5-flash-cyber/"
    ]
  ],
  "category_name": "Frontier-lab and general scanners",
  "page": "https://agentsast.com/tools/big-sleep/",
  "updated": "2026-09-13"
}