CVE-2026-50260 Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in freecounter()

What is CVE-2026-50260?

CVE-2026-50260 is a high-severity use after free vulnerability in Redhat Enterprise Linux, published on 5 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for privilege escalation if the X server runs as root.

Weakness: CWE-416

Which versions are affected by CVE-2026-50260?

It affects 3 products.

Products include Redhat Enterprise Linux, X.org X Server, X.org Xwayland.

How do I fix CVE-2026-50260?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2026-50260 being exploited?

There is no known exploitation of CVE-2026-50260 in the wild and no public exploit code.

Other vulnerabilities in Redhat Enterprise Linux

• CVE-2018-14667 Red Hat JBoss RichFaces Framework Expression Language Injection Exploited Critical 9.8
• CVE-2021-20325 Missing fixes for CVE-2021-40438 and CVE-2021-26691 in the versions of httpd, as shipped in Red Hat Enterprise Linux 8.5.0, causes a securit Critical 9.8
• CVE-2018-25011 Memory corruption in libwebp Critical 9.8
• CVE-2018-25014 Other in libwebp Critical 9.8
• CVE-2014-3585 Supply chain in redhat-upgrade-tool Critical 9.8

All Redhat Enterprise Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-89537, AZL-89577, BELL-CVE-2026-50260, DEBIAN-CVE-2026-50260, ECHO-acf9-4716-8b53, GHSA-7j37-rf7v-jf5c and 1 more.