CVE-2026-64388CWE-682

CVE-2026-64388

High · published July 25, 2026

CVSS v3.1
7.8
EPSS
0%
Percentile
2.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.8 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00129 · 2.3th percentile
Weakness
CWE-682 · Incorrect Calculation
Published
2026-07-25T14:17Z
Affected products (1)
ProductVersionsFixed in
linux/linux_kernel≥ 4.18, < 7.1.47.1.4
References (5)
https://git.kernel.org/stable/c/27ead8c5418af6bfab711079fecb9414d78d4cae · 416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3eaec47518e126e6dcd1a48521d740278073f0ec · 416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/550cfb8a81181331d4d0f76ab75ee58a0bf41e3e · 416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6825a45f6b8ef76b0ee32649ec3d6e39ca143a18 · 416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/760ef2c579c2609cf17fb1cd5392f64d42d43d33 · 416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS history
Timeline
  • 25 JUL 08:50Z
    smb/client: fix chown/chgrp with SMB3 POSIX Extensions
    cvelistv5