CVE-2026-109411 Samba: access control bypass via vfs_ceph_rgw case-insensitive open
Description
An access control bypass flaw was identified in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NExploitable remotely over the network, with an ordinary account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Samba 4.25 | 4.25.0 → < 4.25.1 | 4.25.1 |
| Red Hat Enterprise Linux 10 | Versions not published | |
| Red Hat Enterprise Linux 6 | Versions not published | |
| Red Hat Enterprise Linux 7 | Versions not published | |
| Red Hat Enterprise Linux 8 | Versions not published | |
| Red Hat Enterprise Linux 9 | Versions not published | |
| Red Hat OpenShift Container Platform 4 | Versions not published | |
| Red Hat OpenShift Container Platform 5 | Versions not published |
References
- access.redhat.com access.redhat.com
- attachments.samba.org attachments.samba.org
- attachments.samba.org attachments.samba.org
- RHBZ#2552136 bugzilla.redhat.com
- bugzilla.samba.org bugzilla.samba.org
Timeline
- Published
- Last modified