CVE-2025-26601
A use-after-free flaw was found in X.Org and Xwayland.
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 · 33th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- tigervnc/tigervnc · x.org/x server · x.org/xwayland · redhat/enterprise linux
- Source
- secalert@redhat.com
EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://access.redhat.com/errata/RHSA-2025:2500Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2502Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2861Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2862Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2865Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2866Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2873Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2874Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2875Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2879Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:2880Third Party Advisory
- https://access.redhat.com/errata/RHSA-2025:3976
- https://access.redhat.com/errata/RHSA-2025:7163
- https://access.redhat.com/errata/RHSA-2025:7165
- https://access.redhat.com/errata/RHSA-2025:7458
- https://access.redhat.com/security/cve/CVE-2025-26601Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2345251Issue Tracking
- https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html
- https://security.netapp.com/advisory/ntap-20250516-0004/
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.