CVE Catalog

CVE-2026-64388

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

2th percentile - higher than 2% of all known CVEs

Summary

In the Linux kernel, SMB3 client with POSIX Extensions ignored chown/chgrp changes unless CIFS_MOUNT_CIFS_ACL or CIFS_MOUNT_MODE_FROM_SID were set. The fix checks for posix_extensions in cifs_setattr_nounix() to properly call id_mode_to_cifs_acl() and set ownership/group on the server.

Risk Assessment

The organization may be unable to correctly manage file permissions via SMB3 POSIX, leading to access misconfigurations and potential security breaches.

Recommendation

Update the Linux kernel to a version containing this fix to ensure proper chown/chgrp behavior with SMB3 POSIX Extensions.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: smb/client: fix chown/chgrp with SMB3 POSIX Extensions Ownership (chown) and group (chgrp) modifications were being ignored when mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or CIFS_MOUNT_MODE_FROM_SID were also explicitly set. Fix this by checking for posix_extensions in cifs_setattr_nounix() when updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map and set the ownership/group information on the server.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS