What’s Vulnerable › Vulnerabilities

CVE-2026-4426: Libarchive: libarchive: denial of service via malformed iso file processing

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-19 · updated 2026-09-01
• Weakness: CWE-1335

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.

Affected products

• libarchive: all versions
• Red Hat Enterprise Linux: 6.0, 7.0, 8.0, 9.0, 10.0
• RedHat Hardened Images: all versions
• Red Hat OpenShift Container Platform 4.18: 4.0

References

• https://access.redhat.com/errata/RHSA-2026:8944
• https://access.redhat.com/security/cve/CVE-2026-4426
• https://bugzilla.redhat.com/show_bug.cgi?id=2449010
• https://github.com/libarchive/libarchive/pull/2897

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