SB2026072150 - Unchecked Return Value in Linux kernel nfsd

Description

This security bulletin contains information about 1 vulnerability.

1) Unchecked Return Value (CVE-ID: CVE-2026-53396)

CWE-ID: CWE-252 - Unchecked Return Value

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 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.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/18cf006a08babec0bbac2a3784f8f28e56e47490
• https://git.kernel.org/stable/c/24c975bbdd564d7d0ad90294bfa69729830345de