CVE-2026-50260
Published: June 6, 2026Last modified: June 8, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | xorg-server | Fixed (21.1.23-r0) |
| 25 LTS | xorg-server | Fixed (21.1.23-r0) | |
| Stream | xorg-server | Fixed (21.1.23-r0) |
References
- https://access.redhat.com/security/cve/CVE-2026-50260
- https://bugzilla.redhat.com/show_bug.cgi?id=2485385
- https://gitlab.freedesktop.org/xorg/xserver/-/commit/f5abfb61994471023d8c6470428c8e30c411cc0b
- https://lists.x.org/archives/xorg-announce/2026-June/003702.html
- https://redhat.atlassian.net/browse/PSIRTSUPT-16950