CVE-2026-111497

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.

Read the notes from the security team

Why is this CVE high priority?

CISA-KEV

Learn more about Ubuntu priority

Status

Show unmaintained releases

Package	Ubuntu Release	Status
brotli	26.10 stonking	Fixed in 1.2.0-4ubuntu0.1
	26.04 LTS resolute	Fixed in 1.2.0-3ubuntu0.1
	24.04 LTS noble	Fixed in 1.1.0-2ubuntu0.1
	22.04 LTS jammy	Fixed in 1.0.9-2ubuntu0.1
	20.04 LTS focal	Fixed in 1.0.7-6ubuntu0.1+esm1
	18.04 LTS bionic	Fixed in 1.0.3-1ubuntu1.3+esm1
	16.04 LTS xenial	Fixed in 1.0.3-1ubuntu1~16.04.2+esm1
nodejs	26.10 stonking	Not affected
	26.04 LTS resolute	Not affected
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Vulnerable
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

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Notes

mdeslaur

nodejs on jammy and higher uses the system brotli, marking as not-affected nodejs on focal uses the vendored brotli nodejs in bionic and earlier doesn't use brotli at all

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
brotli	Upstream: b418fa8 Upstream: da98063 Upstream: 50a9b70

Severity score breakdown

CVSS version: CVSS v4.0

Base score 9.2 · Critical

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Attack requirements	Present
Privileges required	None
User interaction	None
Vulnerable system - Confidentiality impact	High
Vulnerable system - Integrity impact	High
Vulnerable system - Availability impact	High
Subsequent system - Confidentiality impact	None
Subsequent system - Integrity impact	None
Subsequent system - Availability impact	None

Scores

Parameter	Value
Base score	9.2 · Critical
Base + Threat score	-
Base + Environmental score	-
Base + Threat + Environmental score	-

Vector: 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

References

Related Ubuntu Security Notices (USN)

USN-8956-1
Brotli vulnerability
26 October 2026

USN-8956-2
Brotli vulnerability
27 October 2026