Unchecked Return Value in Linux kernel - CVE-2026-53396
Published: July 21, 2026
Vulnerability identifier: #VU138874
CSH Severity: Medium
CVSS v4: 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]
CVE-ID: CVE-2026-53396
CWE-ID: CWE-252
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass attribute validation.
The vulnerability exists due to improper check for unusual or exceptional conditions in nfsd4_create_file() when converting NFSv4 ACLs during CREATE processing. A remote attacker can send ACL attributes containing unsupported ACE types to bypass attribute validation.
The server may create the file without any ACL and still return NFS4_OK instead of rejecting unsupported attributes.
Affected software
Linux kernel
How to mitigate CVE-2026-53396
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3