CVE-2026-4426

Publication date 19 March 2026

Last updated 22 May 2026

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw was found in libarchive. An Undefined Behavior vulnerability exists in the zisofs decompression logic, caused by improper validation of a field (`pz_log2_bs`) read from ISO9660 Rock Ridge extensions. A remote attacker can exploit this by supplying a specially crafted ISO file. This can lead to incorrect memory allocation and potential application crashes, resulting in a denial-of-service (DoS) condition.

Status

Show unmaintained releases

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

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Patch details

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

Package	Patch details
libarchive	Upstream: c3cb1c5

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-8292-1
libarchive vulnerabilities
21 May 2026