Cyber Posture

CVE-2026-5121

High

Published: 30 March 2026

Published
30 March 2026
Modified
30 April 2026
KEV Added
Patch
CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0008 24.4th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Description

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

Security Summary

CVE-2026-5121 is an integer overflow vulnerability in the zisofs block pointer allocation logic of libarchive, affecting 32-bit systems. The flaw occurs when processing a specially crafted ISO9660 image, triggering a heap buffer overflow. It has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) and is associated with CWE-190 (Integer Overflow or Wraparound).

A remote attacker can exploit this vulnerability without privileges or user interaction by supplying a malicious ISO9660 image to an application using libarchive for archive extraction or inspection. Successful exploitation could lead to a heap buffer overflow, potentially enabling arbitrary code execution on the affected system with high confidentiality impact.

Red Hat has addressed this issue through multiple security errata, including RHSA-2026:8510, RHSA-2026:8517, RHSA-2026:8521, RHSA-2026:8534, and RHSA-2026:8864, which provide updated packages with fixes for affected libarchive versions in various Red Hat products.

Details

CWE(s)
CWE-190

Affected Products

libarchive
libarchive
all versions
redhat
hardened images
all versions
redhat
openshift container platform
4.0
redhat
enterprise linux
10.0, 6.0, 7.0, 8.0, 9.0

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

The vulnerability allows remote unauthenticated attackers to achieve arbitrary code execution by supplying a malicious ISO9660 image to libarchive-dependent applications, directly mapping to exploitation of public-facing applications.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References