{"id":"CVE-2026-109411","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-109411","summary":"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…","details":"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.","published":"2026-10-28T20:17:17.007","modified":"2026-10-28T20:17:17.137","cvss":{"score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2026-109411"},{"type":"WEB","url":"https://attachments.samba.org/attachment.cgi?id=19294"},{"type":"WEB","url":"https://attachments.samba.org/attachment.cgi?id=19295"},{"type":"WEB","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2552136"},{"type":"WEB","url":"https://bugzilla.samba.org/show_bug.cgi?id=16276"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T20:17:17.137"}}