CVE-2026-50264: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: out-of-bounds heap write in dri2 drigetbuffers/drigetbufferswithformat

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-05 · updated 2026-07-27
Weakness: CWE-787

Description

An out-of-bounds write flaw was found in the X.Org X server and Xwayland in DRIGetBuffers/DRIGetBuffersWithFormat. A client that requests multiple DRI2BufferBackLeft attachments and one DRI2BufferFrontLeft can trigger an out-of-bounds heap write. This may be used to crash the server, or for privilege escalation if the X server runs as root.

Affected products

Red Hat Enterprise Linux: 7.0, 8.0, 9.0, 10.0
xorg-x11-server: before 21.1.23 — fixed in 21.1.23
X.Org xwayland: before 24.1.12 — fixed in 24.1.12

How to fix

Upgrade to a fixed version: xorg-x11-server 21.1.23; X.Org xwayland 24.1.12. Check the vendor advisory for mitigations.

References

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