SB2026091681 - Use-after-free in Linux kernel nfsd
Published: September 16, 2026
Security Bulletin ID
SB2026091681
CSH Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-90036)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to trigger a use-after-free condition.
The vulnerability exists due to use-after-free in the NFSD blocked-lock reaping logic when reaping blocked locks concurrently with client expiration. A remote attacker can cause a client to be freed before nfs4_put_stateowner() dereferences its cl_lock to trigger a use-after-free condition.
Remediation
Install update from vendor's website.