CVE-2025-26601: redhat enterprise_linux Use After Free

Vulnerability summary

CVE-2025-26601 is a high (CVSS 7.8) Use After Free vulnerability in redhat enterprise_linux. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 32% of scored vulnerabilities.

Timeline

1. 25-02-2025
   PublishedVulnerability first disclosed.
2. 29-06-2026
   Last modifiedVulnerability information updated.

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.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.