Integer overflow in Libarchive

CVE-2026-5121

A flaw was found in libarchive. On 32-bit systems, an integer overflow vulnerability exists in the zisofs block pointer allocation logic. A remote attacker can exploit this by providing a specially crafted ISO9660 image, which can lead to a heap buffer overflow. This could potentially allow for arbitrary code execution on the affected system.

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.014 (72.6th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 72.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-5121: held from 0.011 to 0.014.

EPSS over last 30 days · oldest: 0.011 · newest: 0.014 · change: +0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-5121?
CVE-2026-5121 is a high-severity vulnerability in Libarchive, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-03-30.
How severe is CVE-2026-5121?
High severity. CVSS v3 base score is 7.5 out of 10.