CVE-2026-97561

high

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: honor forceuid/forcegid when mapping SIDs to uid/gid When the administrator mounts with forceuid or forcegid (uid=/gid= mount options), they expect all files to appear owned by the specified user/group. However, several code paths unconditionally called sid_to_id() to overwrite cf_uid/cf_gid with server-provided values, ignoring the administrator's explicit override: - smb311_posix_info_to_fattr() (stat via POSIX extensions) - cifs_posix_to_fattr() (readdir via POSIX extensions) - parse_sec_desc() (CIFS ACL ownership mapping) This allowed an untrusted server to dictate local file ownership even when the mount was configured to force specific uid/gid values. Fix all three call sites to check CIFS_MOUNT_OVERR_UID and CIFS_MOUNT_OVERR_GID before calling sid_to_id(), following the same pattern already used by cifs_unix_basic_to_fattr() for unix extensions.

References

https://git.kernel.org/stable/c/e1b74f8f8c1d13190b09fe623b729d36b7ac22a8

https://git.kernel.org/stable/c/6ac7a29691558bed18e2df1780636b8aa0fd13d5

https://git.kernel.org/stable/c/18a72975e9f35aadecc75b031f693f2d1f49308f

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-86869

Details

Source: Mitre, NVD

Published: 2026-09-25

Updated: 2026-10-15

Risk Information

CVSS v2

Base Score: 6.6

Vector: CVSS2#AV:L/AC:M/Au:N/C:P/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00198