{
 "id": "AIR-2026-0562",
 "slug": "cve-2026-40087-langchain-incomplete-f-string-validation-in-p",
 "title": "CVE-2026-40087: LangChain incomplete f-string validation in prompt templates",
 "summary": "LangChain exhibited incomplete prompt template validation where certain classes permitted attribute access or indexing expressions during formatting. This could allow unintended data evaluation within prompt templates.",
 "type": "attack_on_ai",
 "categories": [
  "infra_vuln"
 ],
 "severity": 2,
 "targets": [
  "framework_or_tooling"
 ],
 "products": [
  "LangChain"
 ],
 "incident_date": "2026-04-08",
 "incident_date_precision": "day",
 "first_reported": "2026-04-08",
 "sources": [
  {
   "url": "https://github.com/advisories/GHSA-926x-3r5x-gfhw",
   "publisher": "GitHub Advisory Database",
   "title": "CVE-2026-40087: LangChain has incomplete f-string validation in prompt templates",
   "published_at": "2026-04-08"
  },
  {
   "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40087",
   "publisher": "NVD",
   "title": "CVE-2026-40087: LangChain is a framework for building agents and LLM-powered applications.",
   "published_at": "2026-04-09"
  }
 ],
 "source_count": 2,
 "confidence": 0.95,
 "status": "published",
 "origin": "seed_ghsa",
 "tags": [
  "CVE-2026-40087",
  "prompt-template"
 ],
 "created_at": "2026-10-18T07:00:14.101Z",
 "updated_at": "2026-10-18T10:04:21.885Z"
}