SB20260912118 - Use-after-free in Linux kernel nfsd
Published: September 12, 2026
Security Bulletin ID
SB20260912118
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-89659)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 0 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to trigger a use-after-free.
The vulnerability exists due to a use-after-free in NFSD delegation revocation when an expired recalled delegation is revoked concurrently with client teardown. A remote user can race delegation revocation with client teardown to trigger a use-after-free.
During the race window, the delegation is on neither the client's active-delegation list nor revoked-delegation list.
Remediation
Install update from vendor's website.