CVE intelligence

CVE-2026-4426

Vulnerability intelligence

Published Mar 19, 2026Sources checked Oct 3, 2026

6.5MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-4426 and is rated Medium severity with a CVSS score of 6.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

CBL-Mariner Releases Release Notes

Vendor-listed releases

3.6.1-10
3.7.7-6

CISA KEVNot listedBased on the latest collected catalog

EPSS0.6%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-4426?

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.