CVEvulnerability

CVE-2026-111497

9.2 CRITICAL Known exploited Published 2026-10-22 Modified 2026-10-28 Official page ↗

CISA Known Exploited Vulnerability

Google Brotli Unchecked Return Value Vulnerability — Google Brotli

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.

Added to KEV: 2026-10-27
Remediation due: 2026-11-10
Ransomware use: Unknown
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.
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

Status: Analyzed
Published: 2026-10-22
Last modified: 2026-10-28
Assigner: [email protected]
CVSS 4.0 ([email protected]): 9.2 CRITICAL — CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected]): 9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses: CWE-252, CWE-787

Description

A buffer overflow vulnerability in the Brotli decoder (c/dec/decode.c) in Google Brotli versions 1.0.3 through 1.2.0 on all platforms 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. Users need to update any Brotli libraries or binaries between 1.0.3 through 1.2.0 to the latest available version: 1.0.10 or 1.1.1 or 1.2.1.

Affected configurations

• google brotli (>= 1.0.3 < 1.0.10) • google brotli (>= 1.1.0 < 1.1.1) • google brotli (>= 1.2.0 < 1.2.1) • nodejs node.js (< 22.23.4) • nodejs node.js (>= 23.0.0 < 24.22.1) • nodejs node.js (>= 25.0.0 < 26.12.1) • python-hyper brotlicffi (< 1.2.1.0) • microsoft .net (>= 8.0.0 < 8.0.33) • microsoft .net (>= 9.0.0 < 9.0.22) • microsoft .net (>= 10.0.0 < 10.0.14) • microsoft .net 11.0.0 • debian debian linux 12.0 • istio istio (< 1.29.9) • istio istio (>= 1.30.0 < 1.30.6) • istio istio (>= 1.31.0 < 1.31.2) • anthropic bun (< 1.4.4) • envoyproxy envoy (< 1.37.8) • envoyproxy envoy (>= 1.38.0 < 1.38.6) • envoyproxy envoy (>= 1.39.0 < 1.39.3) • tianocore edk2 (<= 202608) • google woff2 • duckdb duckdb (<= 2.0.0) • clickhouse clickhouse (<= 26.10.2.103) • apache arrow (<= 26.0.0) • apache arrow 27.0.0 • mcmilk 7-zip-zstd (<= 26.02-1.5.7-r2) • 7-zip p7zip (<= 16.02) • andybalholm brotli (< 1.2.7)

Weakness · CWE (2)

CWE-252 Unchecked Return Value weakness
CWE-787 Out-of-bounds Write weakness

References