CVE-2026-4426: Libarchive

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• Libarchive Libarchive: affected versions not specified
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only; version 8.0 only; version 9.0 only; version 10.0 only
• Red Hat Hardened Images: affected versions not specified
• Red Hat Openshift Container Platform: version 4.0 only

Published 2026-03-19. Last modified 2026-09-01.