VulnerabilityModified

CVE-2026-50260

A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter().

HIGH 7.8EPSS 0.15%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.15% probability · 5th percentile
CISA KEV: Not listed
Weakness: CWE-416
Affected: x.org/x server · x.org/xwayland · redhat/enterprise linux
Source: secalert@redhat.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.