{"id":"CVE-2026-85387","aliases":["EUVD-2026-80892","GHSA-pmgv-hgv2-w69h"],"status":"published","title":"Concrete CMS before 9.5.4 allows a deactivated user to retain OAuth-authenticated REST API access","description":"Concrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and did not re-check the state of the account the token had been issued to. The resource server's authorization validator confirmed only that a token existed, had not expired, and had not been explicitly revoked, and deactivating a user did not revoke that user's outstanding tokens. As a result, a deactivated user retained full access to /ccm/api/1.0/* for the remaining lifetime of any token already issued to them. The same gap applied to accounts that had been deleted or locked pending a forced password reset. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Myq Larson for reporting.","severity":{"version":"4.0","score":2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-08","score":0.00261,"percentile":0.18033,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-613"],"published":"2026-09-16T17:12:05Z","modified":"2026-10-28T02:30:42Z","products":[{"vendor":"concrete cms","product":"concrete cms"},{"vendor":"concretecms","product":"concrete_cms"}],"references":[{"url":"https://documentation.concretecms.org/developers/introduction/version-history/954-release-notes","tags":["release-notes","Broken Link","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-85387","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-pmgv-hgv2-w69h"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85387.json","tags":["advisory"]},{"url":"https://github.com/concretecms/concretecms","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-85387","title":"Concrete CMS before 9.5.4 allows a deactivated user to retain OAuth-authenticated REST API access","description":"Concrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and did not re-check the state of the account the token had been issued to. The resource server's authorization validator confirmed only that a token existed, had not expired, and had not been explicitly revoked, and deactivating a user did not revoke that user's outstanding tokens. As a result, a deactivated user retained full access to /ccm/api/1.0/* for the remaining lifetime of any token already issued to them. The same gap applied to accounts that had been deleted or locked pending a forced password reset. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Myq Larson for reporting.","status":"published","published":"2026-09-16T17:12:05.336Z","modified":"2026-09-17T17:32:47.476Z","cvss":[{"version":"4.0","score":2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low","assessor":"cna"}],"cwes":["CWE-613"],"updated_at":"2026-11-02T14:19:52.016971Z"}],"euvd":[{"id":"EUVD-2026-80892","description":"Concrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and did not re-check the state of the account the token had been issued to. The resource server's authorization validator confirmed only that a token existed, had not expired, and had not been explicitly revoked, and deactivating a user did not revoke that user's outstanding tokens. As a result, a deactivated user retained full access to /ccm/api/1.0/* for the remaining lifetime of any token already issued to them. The same gap applied to accounts that had been deleted or locked pending a forced password reset. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Myq Larson for reporting.","status":"published","published":"2026-09-16T17:12:05Z","modified":"2026-09-17T17:32:47Z","cvss":[{"version":"4.0","score":2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low"}],"updated_at":"2026-11-02T17:28:10.833571Z"}],"ghsa":[{"id":"GHSA-pmgv-hgv2-w69h","title":"Concrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and...","description":"Concrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and did not re-check the state of the account the token had been issued to. The resource server's authorization validator confirmed only that a token existed, had not expired, and had not been explicitly revoked, and deactivating a user did not revoke that user's outstanding tokens. As a result, a deactivated user retained full access to /ccm/api/1.0/* for the remaining lifetime of any token already issued to them. The same gap applied to accounts that had been deleted or locked pending a forced password reset. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Myq Larson for reporting.","status":"published","published":"2026-09-16T18:32:06Z","modified":"2026-09-21T18:31:55Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high"},{"version":"4.0","score":2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/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":"low"}],"cwes":["CWE-613"],"updated_at":"2026-11-02T15:12:15.996228Z"}],"nvd":[{"id":"CVE-2026-85387","description":"Concrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and did not re-check the state of the account the token had been issued to. The resource server's authorization validator confirmed only that a token existed, had not expired, and had not been explicitly revoked, and deactivating a user did not revoke that user's outstanding tokens. As a result, a deactivated user retained full access to /ccm/api/1.0/* for the remaining lifetime of any token already issued to them. The same gap applied to accounts that had been deleted or locked pending a forced password reset. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Myq Larson for reporting.","status":"published","published":"2026-09-16T18:17:17.85Z","modified":"2026-09-21T17:51:12.423Z","cvss":[{"version":"4.0","score":2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/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":"low","assessor":"secondary"},{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high","assessor":"primary"}],"cwes":["CWE-613"],"updated_at":"2026-11-02T14:12:48.630594Z"}],"osv":[{"id":"CVE-2026-85387","title":"Concrete CMS before 9.5.4 allows a deactivated user to retain OAuth-authenticated REST API access","description":"Concrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and did not re-check the state of the account the token had been issued to. The resource server's authorization validator confirmed only that a token existed, had not expired, and had not been explicitly revoked, and deactivating a user did not revoke that user's outstanding tokens. As a result, a deactivated user retained full access to /ccm/api/1.0/* for the remaining lifetime of any token already issued to them. The same gap applied to accounts that had been deleted or locked pending a forced password reset. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Myq Larson for reporting.","status":"published","published":"2026-09-16T17:12:05.336Z","modified":"2026-10-28T02:30:42.273649732Z","cvss":[{"version":"4.0","score":2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low"}],"cwes":["CWE-613"],"updated_at":"2026-11-02T15:45:18.825071Z"}]}}