CVE-2026-50259 Memory corruption in Red Hat Enterprise Linux 10

What is CVE-2026-50259?

CVE-2026-50259 is a high-severity memory corruption 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 stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.

Weakness: CWE-121

Which versions are affected by CVE-2026-50259?

It affects 3 products.

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

How do I fix CVE-2026-50259?

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-2026-50259 being exploited?

There is no known exploitation of CVE-2026-50259 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-89546, AZL-89580, BELL-CVE-2026-50259, DEBIAN-CVE-2026-50259, ECHO-0b10-5abb-ec85, GHSA-7ww4-jpp4-x9fw and 1 more.