SB20260827131 - Improper locking in Linux kernel rseq_grant_slice_extension()
Published: August 27, 2026
Security Bulletin ID
SB20260827131
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper locking (CVE-ID: CVE-2026-74749)
CWE-ID: CWE-667 - Improper Locking
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper lock handling in rseq_grant_slice_extension() when handling deferred hrtimer rearm during exit to user mode. A local user can trigger a granted time slice extension to cause a denial of service.
Remediation
Install update from vendor's website.