Chromium CVE-2026-87491: Out of bounds write in V8

{
  "id": "be9db39241d279f69ee9ed471bf9fdfc6fca09b57fcd4638ecb234b3bf6f657e",
  "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-87491",
  "method": "llm",
  "payload": {
    "kind": "other",
    "title": "Chromium CVE-2026-87491: Out of bounds write in V8",
    "summary": "The announcement says Chromium addresses CVE-2026-87491 and notes that an exploit exists in the wild. It does not state a fixed version for Microsoft Edge.",
    "evidence": "Microsoft Edge (Chromium-based) ingests Chromium, which addresses this vulnerability.",
    "products": [
      {
        "name": {
          "value": "Microsoft Edge (Chromium-based)",
          "evidence": "Microsoft Edge (Chromium-based) ingests Chromium, which addresses this vulnerability."
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "fixed_cves": [],
    "related_cves": [
      {
        "value": "CVE-2026-87491",
        "evidence": "Google is aware that an exploit for CVE-2026-87491 exists in the wild."
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "official-microsoft-security-updates",
  "document_id": 26408,
  "published_at": "2026-09-12T04:56:50+00:00"
}