CVE-2023-43787 Libx11: integer overflow in xcreateimage() leading to a heap overflow

High 7.8 Published 10 Oct 2023 Updated 6 Nov 2025

A local attacker can exploit an integer overflow in libX11 to trigger a heap overflow, enabling arbitrary code execution with elevated privileges.

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-2023-43787?

CVE-2023-43787 is a high-severity vulnerability in Fedoraproject Fedora, published on 10 Oct 2023. 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

A vulnerability was found in libX11 due to an integer overflow within the XCreateImage() function. This flaw allows a local user to trigger an integer overflow and execute arbitrary code with elevated privileges.

Weakness: CWE-190, CWE-122

Which versions are affected by CVE-2023-43787?

It affects 3 products.

Products include Fedoraproject Fedora, Redhat Enterprise Linux, X.org Libx11.

How do I fix CVE-2023-43787?

Apply the vendor's patch.

Is CVE-2023-43787 being exploited?

There is no known exploitation of CVE-2023-43787 in the wild and no public exploit code.

All Fedoraproject Fedora vulnerabilities

Sources

Also known as ALPINE-CVE-2023-43787, AZL-31322, BELL-CVE-2023-43787, DEBIAN-CVE-2023-43787, GHSA-8x43-mjg3-6x36, JLSEC-2026-475 and 1 more.