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.
CVE-2025-26601
CVSS base score
7.8 (v3.1)
Severity
HIGH
Attack vector
Local
Weakness
CWE-416
Last modified
November 4, 2026
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
tigervnc tigervnc
x.org x server
x.org xwayland
redhat enterprise linux
References
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory