Inefficient Algorithmic Complexity in Linux kernel - CVE-2026-89695
Published: September 12, 2026
Vulnerability identifier: #VU149112
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89695
CWE-ID: CWE-407
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient algorithmic complexity in nfsd4_decode_posixacl() when processing an NFSv4 POSIX ACL with a user-controlled entry count. A remote attacker can submit an ACL with a large entry count to cause a denial of service.
The entry count is used by a quadratic bubble sort during NFS server compound request processing.
Affected software
Linux kernel
How to mitigate CVE-2026-89695
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3