CRITICAL · CVSS 9.2
ACTIVELY EXPLOITED
PATCH AVAILABLE
CVE-2026-111497: Google Brotli Unchecked Return Value Vulnerability
| Vendor | |
|---|---|
| Product | Brotli |
| CVSS score | 9.2 · CVSS 4.0 · CRITICALCVSS: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 |
| EPSS | 82.6% (percentile 100) |
| Actively exploited | Yes, according to CISA KEV |
| Added to CISA KEV | 27 Oct 2026 |
| CISA federal deadline | 10 Nov 2026 |
| Weakness (CWE) | CWE-252, CWE-787 |
| NVD published | 22 Oct 2026 |
| NVD last modified | 10 Nov 2026 |
| NVD status | Analyzed |
Affected versions
| Product | Affected versions | Fixed in |
|---|---|---|
| 7-Zip P7Zip | up to 16.02 | – |
| Andybalholm Brotli | before 1.2.7 | 1.2.7 |
| Anthropic Bun | before 1.4.4 | 1.4.4 |
| Apache Arrow | up to 26.0.0 | – |
| Apache Arrow | 27.0.0 | – |
| Clickhouse Clickhouse | up to 26.10.2.103 | – |
| Duckdb Duckdb | up to 2.0.0 | – |
| Envoyproxy Envoy | before 1.37.8 | 1.37.8 |
| Envoyproxy Envoy | from 1.38.0 before 1.38.6 | 1.38.6 |
| Envoyproxy Envoy | from 1.39.0 before 1.39.3 | 1.39.3 |
| Google Brotli | from 1.0.3 before 1.0.10 | 1.0.10 |
| Google Brotli | from 1.1.0 before 1.1.1 | 1.1.1 |
| Google Brotli | from 1.2.0 before 1.2.1 | 1.2.1 |
| Google Woff2 | – | – |
| Istio Istio | before 1.29.9 | 1.29.9 |
| Istio Istio | from 1.30.0 before 1.30.6 | 1.30.6 |
| Istio Istio | from 1.31.0 before 1.31.2 | 1.31.2 |
| Mcmilk 7-Zip-Zstd | up to 26.02-1.5.7-r2 | – |
| Microsoft .Net | from 10.0.0 before 10.0.14 | 10.0.14 |
| Microsoft .Net | from 8.0.0 before 8.0.33 | 8.0.33 |
+30 more
Required action (CISA's text)
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.
Description (NVD)
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.
Vendor advisories
- Vulnerabilities in Node.js and Brotli Affecting Cisco Products: October 2026
- Node2Shell CVEs
- Google: CVE-2026-111497 Buffer overflow vulnerability in the Brotli decoder
SOURCES
Other Google flaws
- CVE-2026-125350: Google Chromium Use-After-Free Vulnerability
- CVE-2026-58704: Google Pixel Improper Authorization Vulnerability
- CVE-2026-87491: Google Chromium V8 Out of Bounds Write Vulnerability
- CVE-2026-85046: Google Chromium V8 Type Confusion Vulnerability
- CVE-2026-11645: Google Chromium V8 Out-of-Bounds Read and Write Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.