Vulnerability 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 Score
HIGH
Related Weaknesses (CWE)
References
- https://access.redhat.com/security/cve/CVE-2026-109411
- https://attachments.samba.org/attachment.cgi?id=19294
- https://attachments.samba.org/attachment.cgi?id=19295
- https://bugzilla.redhat.com/show_bug.cgi?id=2552136
- https://bugzilla.samba.org/show_bug.cgi?id=16276
FAQ
What is CVE-2026-109411?
CVE-2026-109411 is a vulnerability with a CVSS score of 8.1 (HIGH). 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 ...
How severe is CVE-2026-109411?
CVE-2026-109411 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-109411?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.