CVE-2026-109411

An access control bypass flaw was found 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

8.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CWE

CWE-178

Published

2026-10-28

Modified

2026-10-28

Record from

the NVD, synced 2026-10-28

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

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