CVE-2026-64388
kernel: smb/client: fix chown/chgrp with SMB3 POSIX Extensions
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · July 25, 2026
Updated · July 30, 2026
Description
A flaw was found in the Linux kernel's Server Message Block (SMB) client. When mounting filesystems using SMB3 POSIX Extensions, modifications to file ownership (chown) and group (chgrp) were not correctly applied on the server unless specific mount options were also enabled. This could allow a local user to set incorrect file permissions, potentially leading to unauthorized access to sensitive information or unintended privilege escalation.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-279 · Incorrect Execution-Assigned Permissions