SB20260912122 - Use-after-free in Linux kernel nfsd
Published: September 12, 2026
Security Bulletin ID
SB20260912122
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Partial DoS
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-89663)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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 NFS server copy-notify stateid revocation logic when revoking copy-notify stateids while concurrent holders retain references. A remote attacker can trigger concurrent copy-notify stateid revocation to cause a denial of service.
The issue involves parent-stateid draining, OFFLOAD_CANCEL handling, and laundromat expiry.
Remediation
Install update from vendor's website.