Google Brotli Unchecked Return Value Vulnerability

{
  "id": "eed41bbbe81487c2cab93c0e56a9bf609445a825eb62a009b67232510320fc77",
  "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-111497",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Google Brotli Unchecked Return Value Vulnerability",
    "summary": "Google Brotli contains an unchecked return value vulnerability that allows a remote unauthenticated attacker to corrupt adjacent decoder state memory, disclose sensitive memory contents, cause a denial of service, or potentially execute arbitrary code using a crafted Brotli-compressed stream. CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
    "evidence": "kev:CVE-2026-111497",
    "products": [
      {
        "name": {
          "value": "Brotli",
          "evidence": "/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-111497",
      "aliases": [
        "CVE-2026-111497"
      ],
      "affected": [],
      "modified": "2026-10-27T00:00:00.000Z",
      "provider": "kev",
      "references": [
        "https://www.cisa.gov/known-exploited-vulnerabilities-catalog"
      ],
      "exploitation": {
        "cwes": [
          "CWE-252",
          "CWE-787"
        ],
        "cveID": "CVE-2026-111497",
        "notes": "This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: https://github.com/google/brotli/releases/tag/v1.2.1 ; ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-111497",
        "dueDate": "2026-11-10",
        "product": "Brotli",
        "dateAdded": "2026-10-27",
        "vendorProject": "Google",
        "requiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
        "known_exploited": true,
        "shortDescription": "Google Brotli contains an unchecked return value vulnerability that allows a remote unauthenticated attacker to corrupt adjacent decoder state memory, disclose sensitive memory contents, cause a denial of service, or potentially execute arbitrary code using a crafted Brotli-compressed stream.",
        "vulnerabilityName": "Google Brotli Unchecked Return Value Vulnerability",
        "knownRansomwareCampaignUse": "Unknown"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-111497",
        "evidence": "/cveID"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-kev",
  "document_id": 398129,
  "published_at": "2026-10-27T00:00:00+00:00"
}