CVE-2026-5121

Publication date 30 March 2026

Last updated 22 May 2026

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw was found in libarchive. On 32-bit systems, an integer overflow vulnerability exists in the zisofs block pointer allocation logic. A remote attacker can exploit this by providing a specially crafted ISO9660 image, which can lead to a heap buffer overflow. This could potentially allow for arbitrary code execution on the affected system.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libarchive	26.04 LTS resolute	Fixed in 3.8.5-1ubuntu2.1
	25.10 questing	Fixed in 3.7.7-0ubuntu3.2
	24.04 LTS noble	Fixed in 3.7.2-2ubuntu0.7
	22.04 LTS jammy	Fixed in 3.6.0-1ubuntu1.7
	20.04 LTS focal	Fixed in 3.4.0-2ubuntu1.5+esm2
	18.04 LTS bionic	Fixed in 3.2.2-3.1ubuntu0.7+esm3
	16.04 LTS xenial	Fixed in 3.1.2-11ubuntu0.16.04.8+esm3
	14.04 LTS trusty	Fixed in 3.1.2-7ubuntu2.8+esm5

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Notes

mdeslaur

as of 2026-04-10, no fix available from libarchive developers

Patch details

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

Package	Patch details
libarchive	Upstream: a2a73a8

Severity score breakdown

CVSS version: CVSS v3.0

Base score 9.8 · Critical

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	High
Integrity impact	High
Availability impact	High

Scores

Parameter	Value
Base score	9.8 · Critical
Exploitability score	-
Impact score	-