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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 30 Oct 2026 12:45:00 +0000


Wed, 21 Oct 2026 13:15:00 +0000


Thu, 15 Oct 2026 13:30:00 +0000


Thu, 01 Oct 2026 09:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-640

Tue, 29 Sep 2026 13:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-708
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Fri, 25 Sep 2026 23:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-640

Fri, 25 Sep 2026 10:30:00 +0000

Type Values Removed Values Added
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.
Title smb: client: honor forceuid/forcegid when mapping SIDs to uid/gid
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-30T12:37:25.329Z

Reserved: 2026-09-24T16:01:01.155Z

Link: CVE-2026-97561

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-25T11:17:06.657

Modified: 2026-10-30T13:21:08.230

Link: CVE-2026-97561

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-25T00:00:00Z

Links: CVE-2026-97561 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-01T11:00:06Z

Weaknesses