SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2025-26601

A use-after-free flaw was found in X.Org and Xwayland.

HIGH 7.8EPSS 0.39%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). 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 X.Org and Xwayland. When changing an alarm, the values of the change mask are evaluated one after the other, changing the trigger values as requested, and eventually, SyncInitTrigger() is called. If one of the changes triggers an error, the function will return early, not adding the new sync object, possibly causing a use-after-free when the alarm eventually triggers.

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
0.39% probability · 32th percentile
CISA KEV
Not listed
Weakness
CWE-416
Affected
tigervnc/tigervnc · x.org/x server · x.org/xwayland · redhat/enterprise linux
Source
secalert@redhat.com

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