SB20260912121 - Use-after-free in Linux kernel nfsd
Published: September 12, 2026
Security Bulletin ID
SB20260912121
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-89662)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in the NFSD __destroy_client() function when processing DESTROY_CLIENTID requests. A remote attacker can trigger client teardown while blocked locks are reaped to cause a denial of service.
The race can result in a NULL dereference in remove_blocked_locks().
Remediation
Install update from vendor's website.