{"id":"CVE-2026-6826","aliases":["EUVD-2026-31344","GHSA-4g7q-44qp-cc5c"],"status":"published","title":"Concrete 9.5.0 and below has file usage disclosure via missing permission check in Usage controller","description":"Concrete CMS 9.5.0 and below  is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.  Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions.The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.9 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01461,"percentile":0.73934,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-200"],"published":"2026-05-21T20:55:21Z","modified":"2026-10-28T02:30:53Z","exploits":[{"source":"metasploit","id":"auxiliary/scanner/http/concrete_cms_file_usage_disclosure","title":"Concrete CMS Unauthenticated File Usage Disclosure","type":"auxiliary","date":"2026-05-21","verified":true,"url":"https://www.rapid7.com/db/modules/auxiliary/scanner/http/concrete_cms_file_usage_disclosure"},{"source":"nuclei","id":"CVE-2026-6826","title":"Concrete CMS \u003c9.5.1 - Unauthenticated File Usage Disclosure","type":"detection template","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-6826.yaml"}],"fixes":[{"ecosystem":"Packagist","package":"concrete5/concrete5","fixed_in":["9.5.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"concrete5/concrete5","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.5.1"}]}]},{"source":"osv","ecosystem":"Packagist","package":"concrete5/concrete5","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.5.1"}]}],"versions":["8.0","8.0.1","8.0.2","8.0.3","8.1.0","8.2.0","8.2.0RC2","8.2.1","8.3.0","8.3.1","8.3.2","8.4.0","8.4.0RC3","8.4.0RC4","8.4.1","8.4.2","8.4.3","8.4.4","8.4.5","8.5.0","8.5.0RC1","8.5.0RC2","8.5.1","8.5.10","8.5.11","8.5.12","8.5.13","8.5.14","8.5.15","8.5.16","8.5.17","8.5.18","8.5.19","8.5.2","8.5.20","8.5.21","8.5.3","8.5.4","8.5.5","8.5.6","8.5.6RC1","8.5.7","8.5.8","8.5.9","9.0.0","9.0.0RC1","9.0.0RC3","9.0.0RC4","9.0.1","9.0.2","9.1.0","9.1.1","9.1.2","9.1.3","9.2.0","9.2.0RC2","9.2.1","9.2.2","9.2.3","9.2.4","9.2.5","9.2.6","9.2.7","9.2.8","9.2.9","9.3.0","9.3.1","9.3.2","9.3.3","9.3.4","9.3.5","9.3.6","9.3.7","9.3.8","9.3.9","9.4.0","9.4.0RC1","9.4.0RC2","9.4.1","9.4.2","9.4.3","9.4.4","9.4.5","9.4.6","9.4.7","9.4.8","9.5.0","9.5.0RC1","9.5.0RC2"]}],"products":[{"vendor":"concrete cms","product":"concrete cms"},{"vendor":"concretecms","product":"concrete_cms"}],"references":[{"url":"https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes","tags":["release-notes","Release Notes","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6826","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4g7q-44qp-cc5c"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6826.json","tags":["advisory"]},{"url":"https://github.com/concretecms/concretecms","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-6826","title":"Concrete 9.5.0 and below has file usage disclosure via missing permission check in Usage controller","description":"Concrete CMS 9.5.0 and below  is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.  Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions.The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.9 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.","status":"published","published":"2026-05-21T20:55:21.936Z","modified":"2026-05-22T12:27:12.181Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T13:50:04.986624Z"}],"euvd":[{"id":"EUVD-2026-31344","description":"Concrete CMS 9.5.0 and below  is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.  Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions.The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.9 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.","status":"published","published":"2026-05-21T20:55:21Z","modified":"2026-05-22T12:27:12Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:21:12.869457Z"}],"ghsa":[{"id":"GHSA-4g7q-44qp-cc5c","title":"Concrete CMS is vulnerable to unauthenticated file usage disclosure","description":"Concrete CMS 9.5.0 and below  is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.  Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions. Concrete CMS thanks Eldudareeno for reporting this issue.","status":"published","published":"2026-05-21T21:30:37Z","modified":"2026-06-23T22:57:23Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:40:32.744157Z"}],"nvd":[{"id":"CVE-2026-6826","description":"Concrete CMS 9.5.0 and below  is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.  Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions.The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.9 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.","status":"published","published":"2026-05-21T21:16:32.697Z","modified":"2026-07-23T16:10:00.137Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:12:19.752984Z"}],"osv":[{"id":"CVE-2026-6826","title":"Concrete 9.5.0 and below has file usage disclosure via missing permission check in Usage controller","description":"Concrete CMS 9.5.0 and below  is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.  Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions.The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.9 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.","status":"published","published":"2026-05-21T20:55:21.936Z","modified":"2026-10-28T02:30:53.820540774Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T15:45:14.808935Z"},{"id":"GHSA-4g7q-44qp-cc5c","title":"Concrete CMS is vulnerable to unauthenticated file usage disclosure","description":"Concrete CMS 9.5.0 and below  is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.  Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions. Concrete CMS thanks Eldudareeno for reporting this issue.","status":"published","published":"2026-05-21T21:30:37Z","modified":"2026-09-10T03:51:04.524880771Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T15:46:36.782754Z"}]}}