# CVE-2026-4426

## Summary

- **CVE ID:** CVE-2026-4426
- **Severity:** MEDIUM
- **CVSS Score:** 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H)
- **CWE:** CWE-1335
- **Published:** Mar 19, 2026
- **Last Modified:** Sep 1, 2026

## 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

- Red Hat — Red Hat Hardened Images (3.8.7-1.hum1)

## References

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

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.30%
- **EPSS Percentile:** 23.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._