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.
Remediation
CISA required actionApply 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.
References
- Patchhttps://nodejs.org/en/blog/vulnerability/october-2026-security-releases#nodejs-brotli-decoder-out-of-bounds-write-permits-remote-code-execution-cve-2026-111497---high
- Advisoryhttps://github.com/advisories/GHSA-9v8h-qqgm-4m35
- Advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-111497
- Advisoryhttps://github.com/google/brotli/releases/tag/v1.2.1
- Advisoryhttps://github.com/dotnet/announcements/issues/494
- Advisoryhttps://www.aikido.dev/blog/node2shell-nodejs-brotli-rce-cve-2026-111497
- Advisoryhttps://patchtheplanet.org/brotli
- Advisoryhttps://lists.debian.org/debian-lts-announce/2026/10/msg00049.html
- Advisoryhttps://github.com/andybalholm/brotli/releases/tag/v1.2.7
- Advisoryhttps://broccoli2shell.com
- Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk