SB20260912114 - Improper input validation in Linux kernel nfsd
Published: September 12, 2026
Security Bulletin ID
SB20260912114
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper input validation (CVE-ID: CVE-2026-89671)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to remove POSIX ACLs.
The vulnerability exists due to improper input validation in nfsd3_proc_setacl() when processing NFSv3 SETACL requests with omitted ACL mask bits. A remote attacker can send a SETACL request with omitted ACL mask bits to remove POSIX ACLs.
Remediation
Install update from vendor's website.