CVE-2026-50261

Summary

A use-after-free flaw was found in the X.Org X server and Xwayland in SyncChangeCounter(). A client that sets up multiple SyncCounters can trigger a use-after-free when destroying those counters via a second client connection while changing those counters. This may be used to crash the server, or for privilege escalation if the X server runs as root.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat Enterprise Linux 100:24.1.9-4.el10_2.2 < *unaffected
Red HatRed Hat Enterprise Linux 80:21.1.3-20.el8_10.2 < *unaffected
Red HatRed Hat Enterprise Linux 80:1.20.11-28.el8_10.2 < *unaffected
Red HatRed Hat Enterprise Linux 80:1.15.0-10.el8_10 < *unaffected
Red HatRed Hat Enterprise Linux 90:24.1.9-4.el9_8.2 < *unaffected
Red HatRed Hat Enterprise Linux 90:1.20.11-34.el9_8.2 < *unaffected
Red HatRed Hat Enterprise Linux 90:1.15.0-7.el9_8.2 < *unaffected

Weaknesses

  • CWE-416: Use After Free

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in SyncChangeCounter()

Additional References

References