CVE-2026-64388 Details
Description
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.
A vulnerability in the Linux kernel's SMB client implementation has been addressed. When mounting with SMB3 POSIX Extensions, ownership (chown) and group (chgrp) modifications were ignored unless CIFS_MOUNT_CIFS_ACL or CIFS_MOUNT_MODE_FROM_SID were explicitly set. The issue has been fixed by ensuring that the presence of POSIX extensions is considered when updating UID and GID, allowing for proper mapping and setting of ownership and group information on the server.
Users can apply the latest patch available in the Linux kernel stable tree to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/550cfb8a81181331d4d0f76ab75ee58a0bf41e3e | kernel.org | Patch |
| https://git.kernel.org/stable/c/760ef2c579c2609cf17fb1cd5392f64d42d43d33 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| NVD-CWE-noinfo | Insufficient Information to Classify Weakness | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 4.18, < 7.1.4 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 4, 2026 | Initial Analysis | [email protected] |
| Aug 17, 2026 | CVE Modified | kernel.org |
| Jul 27, 2026 | CVE Modified | kernel.org |
| Jul 25, 2026 | New CVE Received | kernel.org |