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CVE-2026-50260 Red Hat CVE debrief

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.

Vendor
Red Hat
Product
Red Hat Enterprise Linux 10
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-05
Original CVE updated
2026-06-11
Advisory published
2026-06-05
Advisory updated
2026-06-11

Who should care

Users of X.Org X server and Xwayland should apply patches or mitigations to address this vulnerability.

Technical summary

The vulnerability has a CVSS score of 7.8 and is classified as HIGH severity. The CVSS vector is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. The weakness is CWE-416.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches or updates from vendors
  • Restrict access to the X server
  • Monitor for suspicious activity

Evidence notes

The vulnerability was published on 2026-06-05T12:16:39.430Z and modified on 2026-06-11T18:36:20.720Z.

Official resources

CVE-2026-50260 was published on 2026-06-05T12:16:39.430Z and modified on 2026-06-11T18:36:20.720Z.