CVE-2026-56001 libXfont2 BitmapScaleBitmaps Integer Overflow Heap Buffer Overflow

High 8.5 Published 8 Jul 2026 Updated 9 Jul 2026

An integer overflow in libXfont2 allows attackers with X Server access to execute arbitrary code via a heap buffer overflow.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-56001?

CVE-2026-56001 is a high-severity vulnerability in X.Org libXfont2, published on 8 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A heap buffer overflow in BitmapScaleBitmaps in libXfont2 before 2.0.8 due to an overflowing 32bit size could be used by attackers able to access the X Server to execute code within the X server cont

Weakness: CWE-122

Which versions are affected by CVE-2026-56001?

It affects 1 product.

Products include X Libxfont.

How do I fix CVE-2026-56001?

Upgrade to a fixed version.

Is CVE-2026-56001 being exploited?

There is no known exploitation of CVE-2026-56001 in the wild and no public exploit code.

Sources

Also known as AZL-92081, BELL-CVE-2026-56001, DEBIAN-CVE-2026-56001, ECHO-fe44-fa4e-c5aa, GHSA-j726-7g32-78m6, UBUNTU-CVE-2026-56001.