# CVE-2026-50264: X.Org X server and Xwayland out-of-bounds write in DRI2

Source: https://junglewise.ai/threats/cve-2026-50264-x-org-x-server-and-xwayland-out-of-bounds-write-in-dri2  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-05. Updated: 2026-06-05  
License: CC BY 4.0 with a link back

CVE-2026-50264 · Severity: high · CVSS 7.8 · Published 2026-06-05

A security vulnerability has been identified in the X.Org X server and Xwayland, which are fundamental components used to manage graphical displays and user input on Linux systems. A local user or malicious application could exploit this flaw to crash the system or potentially gain administrative (root) privileges. This could lead to a complete takeover of the affected machine or a disruption of services.

Technologies: [X.Org Foundation Xorg-X11-Server](https://junglewise.ai/threats/technologies/x-server). Vendors: [X.Org Foundation](https://junglewise.ai/threats/vendors/x-org-foundation).

## Quick answers

**Is CVE-2026-50264 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-50264 being exploited in the wild.

**How severe is CVE-2026-50264?** High severity, with a CVSS score of 7.8, published 5 June 2026.

**Which products and versions are affected?** X.Org Foundation Xorg-X11-Server <= 21.1.22.

**Is there a fix for CVE-2026-50264?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-50264 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-50264?** Check whether you run X.Org Foundation Xorg-X11-Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds (OOB) heap write vulnerability exists in the DRIGetBuffers and DRIGetBuffersWithFormat functions within the DRI2 module of the X.Org X server and Xwayland. The flaw is triggered when a client requests multiple DRI2BufferBackLeft attachments alongside a DRI2BufferFrontLeft attachment, leading to an incorrect buffer allocation size that does not account for duplicate attachments. A local attacker with the ability to connect to the X server can exploit this to corrupt heap memory, potentially achieving arbitrary code execution with the privileges of the X server (often root). The issue has been addressed in xorg-server version 21.1.23 and xwayland version 24.1.12 by implementing attachment deduplication using a bit-set.

## Affected products

- X.Org xorg-x11-server <= 21.1.22
- X.Org xorg-x11-server-Xwayland <= 24.1.9

## Timeline

- 2026-05-15: other: Fix authored upstream
- 2026-06-01: other: Fix committed upstream
- 2026-06-02: advisory: X.Org security advisory released
- 2026-06-05: disclosed: CVE published and Red Hat advisory issued

## References

- [https://access.redhat.com/security/cve/CVE-2026-50264](https://access.redhat.com/security/cve/CVE-2026-50264)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2485389](https://bugzilla.redhat.com/show_bug.cgi?id=2485389)
- [https://gitlab.freedesktop.org/xorg/xserver/-/commit/339c279514326134b0878fc23ce6e9520440ce7f](https://gitlab.freedesktop.org/xorg/xserver/-/commit/339c279514326134b0878fc23ce6e9520440ce7f)
- [https://lists.x.org/archives/xorg-announce/2026-June/003702.html](https://lists.x.org/archives/xorg-announce/2026-June/003702.html)
- [https://redhat.atlassian.net/browse/PSIRTSUPT-16950](https://redhat.atlassian.net/browse/PSIRTSUPT-16950)