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Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 : Brotli vulnerability (USN-8956-1)

critical Nessus Plugin ID 372415

Synopsis

The remote Ubuntu host is missing a security update.

Description

The remote Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 host has packages installed that are affected by a vulnerability as referenced in the USN-8956-1 advisory.

 It was discovered that Brotli incorrectly handled certain compressed streams. A remote attacker could possibly use this issue to cause a denial of service or execute arbitrary code.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected brotli, libbrotli1 and / or python3-brotli packages.

See Also

https://ubuntu.com/security/notices/USN-8956-1

Plugin Details

Severity: Critical

ID: 372415

File Name: ubuntu_USN-8956-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 10/27/2026

Updated: 10/27/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.9

Percentile: 99.33

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2026-111497

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS v4

Risk Factor: Critical

Base Score: 9.2

Threat Score: 8.2

Threat Vector: CVSS:4.0/E:P

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.10, p-cpe:/a:canonical:ubuntu_linux:brotli, p-cpe:/a:canonical:ubuntu_linux:libbrotli1, p-cpe:/a:canonical:ubuntu_linux:python3-brotli

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 10/26/2026

Vulnerability Publication Date: 10/21/2026

Reference Information

CVE: CVE-2026-111497

IAVA: 2026-A-1200

USN: 8956-1