CVE-2026-62423 buffer overruns in libfsimage iso9660 handling

Medium 5.5 Published Updated

Attackers can trigger buffer overruns in Xen's libfsimage iso9660 driver via crafted disk images, potentially leading to code execution or denial of service.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Local or same network only
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2026-62423?

CVE-2026-62423 is a medium-severity memory corruption vulnerability in Xen, published on 28 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.]

The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver derives several lengths directly from attacker-controlled on-disk fields without validating them:

* The directory loop itself assumes a good record length. This is CVE-2026-42494.

* The calculation of the System Use area may underflow. This is CVE-2026-42495.

* The Rock Ridge extension loop assumes a good (inner) record length. This is CVE-2026-62423.

* The Rock Ridge NM record processing assumes a good entry length. This is CVE-2026-62424.

* The Rock Ridge CE record processing assumes a good size and offset. This is CVE-2026-62425.

Weakness: CWE-130

Which versions are affected by CVE-2026-62423?

How do I fix CVE-2026-62423?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-62423 being exploited?

There is no known exploitation of CVE-2026-62423 in the wild and no public exploit code.

Sources

Also known as ALPINE-CVE-2026-62423, DEBIAN-CVE-2026-62423, GHSA-wgq7-83qv-q9cw, UBUNTU-CVE-2026-62423.

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