{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-109411","assignerOrgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","state":"PUBLISHED","assignerShortName":"redhat","dateReserved":"2026-10-12T15:19:07.605Z","datePublished":"2026-10-28T19:17:45.459Z","dateUpdated":"2026-10-30T05:04:35.990Z"},"containers":{"cna":{"title":"Samba: access control bypass via vfs_ceph_rgw case-insensitive open","metrics":[{"other":{"content":{"value":"Important","namespace":"https://access.redhat.com/security/updates/classification/"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"format":"CVSS"}],"descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Samba","product":"Samba","versions":[{"status":"affected","version":"4.25.0","lessThan":"4.25.1","versionType":"semver"}],"packageName":"samba","collectionURL":"https://gitlab.com/samba-team/samba","defaultStatus":"unaffected"},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"samba","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"samba","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"samba4","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"samba","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"samba","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"samba","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:9"]},{"vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"openshift/ose-rhel-coreos-8","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:openshift:4"]},{"vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"openshift/ose-rhel-coreos-9","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:openshift:4"]},{"vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 5","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"openshift/ose-rhel-coreos-9","defaultStatus":"unaffected","cpes":["cpe:/a:redhat:openshift:5"]}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-109411","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://attachments.samba.org/attachment.cgi?id=19294"},{"url":"https://attachments.samba.org/attachment.cgi?id=19295"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2552136","name":"RHBZ#2552136","tags":["issue-tracking","x_refsource_REDHAT"]},{"url":"https://bugzilla.samba.org/show_bug.cgi?id=16276"}],"datePublic":"2026-10-23T15:00:00.000Z","problemTypes":[{"descriptions":[{"cweId":"CWE-178","description":"Improper Handling of Case Sensitivity","lang":"en","type":"CWE"}]}],"x_redhatCweChain":"CWE-178: Improper Handling of Case Sensitivity","workarounds":[{"lang":"en","value":"Only shares configured with the vfs_ceph_rgw module are affected.\n\nTo mitigate this vulnerability, disable the experimental `vfs_ceph_rgw` module on any configured Samba shares. Edit `/etc/samba/smb.conf` to remove `ceph_rgw` from the `vfs objects` setting under the relevant share sections, then reload the Samba service:\n\n```\nsystemctl reload smb\n```\n\nWarning: Reloading or restarting the `smb` service may briefly interrupt active client sessions. Additionally, removing this module disables Ceph RGW integration for the affected shares.\n\nSetting ```case sensitive = yes``` on affected shares avoids the vulnerability, because the differently-cased name is then treated as a distinct object rather than resolving to the existing file. \n\nNote: This changes share behavior for clients that rely on case-insensitive name handling."}],"timeline":[{"lang":"en","time":"2026-10-14T00:00:00.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-10-23T15:00:00.000Z","value":"Made public."}],"credits":[{"lang":"en","value":"Red Hat would like to thank hataehoon for reporting this issue."}],"providerMetadata":{"orgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","shortName":"redhat","dateUpdated":"2026-10-30T05:04:35.990Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-29T15:36:56.528765Z","id":"CVE-2026-109411","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-29T20:54:00.468Z"}}]}}