CVE-2026-64388
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
25/07/2026
Last modified:
27/07/2026
Description
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
smb/client: fix chown/chgrp with SMB3 POSIX Extensions<br />
<br />
Ownership (chown) and group (chgrp) modifications were being ignored when<br />
mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or<br />
CIFS_MOUNT_MODE_FROM_SID were also explicitly set.<br />
<br />
Fix this by checking for posix_extensions in cifs_setattr_nounix() when<br />
updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map<br />
and set the ownership/group information on the server.
Impact
Base Score 3.x
7.80
Severity 3.x
HIGH