{"id":"CVE-2026-81901","aliases":["EUVD-2026-78089","GHSA-c3pr-6qr9-9226"],"status":"published","title":"Concrete CMS 9.2.0 to 9.5.2 is vulnerable to stored XSS due to missing authorization in the `PUT /pages/{cID}` endpoint","description":"In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the API, and could set the header_extra_content attribute, which is rendered unescaped into the head element of every page, to persist JavaScript that executed in the browser of every visitor, including higher-privileged reviewers who approve the page version. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.2 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.","severity":{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00383,"percentile":0.32788,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-862"],"published":"2026-09-14T20:38:54Z","modified":"2026-11-11T02:31:02Z","products":[{"vendor":"concrete cms","product":"concrete cms"},{"vendor":"concretecms","product":"concrete_cms"}],"references":[{"url":"https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes","tags":["release-notes","Broken Link","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-81901","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-c3pr-6qr9-9226"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81901.json","tags":["advisory"]},{"url":"https://github.com/concretecms/concretecms","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-81901","title":"Concrete CMS 9.2.0 to 9.5.2 is vulnerable to stored XSS due to missing authorization in the `PUT /pages/{cID}` endpoint","description":"In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the API, and could set the header_extra_content attribute, which is rendered unescaped into the head element of every page, to persist JavaScript that executed in the browser of every visitor, including higher-privileged reviewers who approve the page version. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.2 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.","status":"published","published":"2026-09-14T20:38:54.393Z","modified":"2026-09-15T14:23:36.718Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T13:36:29.327819Z"}],"euvd":[{"id":"EUVD-2026-78089","description":"In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the API, and could set the header_extra_content attribute, which is rendered unescaped into the head element of every page, to persist JavaScript that executed in the browser of every visitor, including higher-privileged reviewers who approve the page version. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.2 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.","status":"published","published":"2026-09-14T20:38:54Z","modified":"2026-09-15T14:23:36Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T17:28:18.105573Z"}],"ghsa":[{"id":"GHSA-c3pr-6qr9-9226","title":"In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/...","description":"In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the API, and could set the header_extra_content attribute, which is rendered unescaped into the head element of every page, to persist JavaScript that executed in the browser of every visitor, including higher-privileged reviewers who approve the page version. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.2 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.","status":"published","published":"2026-09-14T21:31:51Z","modified":"2026-09-18T21:33:00Z","cvss":[{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high"},{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/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":"high"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T15:12:12.782251Z"}],"nvd":[{"id":"CVE-2026-81901","description":"In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the API, and could set the header_extra_content attribute, which is rendered unescaped into the head element of every page, to persist JavaScript that executed in the browser of every visitor, including higher-privileged reviewers who approve the page version. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.2 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.","status":"published","published":"2026-09-14T21:17:26.123Z","modified":"2026-09-18T19:17:29.047Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/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":"high","assessor":"secondary"},{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high","assessor":"primary"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T14:12:47.335523Z"}],"osv":[{"id":"CVE-2026-81901","title":"Concrete CMS 9.2.0 to 9.5.2 is vulnerable to stored XSS due to missing authorization in the `PUT /pages/{cID}` endpoint","description":"In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the API, and could set the header_extra_content attribute, which is rendered unescaped into the head element of every page, to persist JavaScript that executed in the browser of every visitor, including higher-privileged reviewers who approve the page version. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.2 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.","status":"published","published":"2026-09-14T20:38:54.393Z","modified":"2026-11-11T02:31:02.396401999Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-862"],"updated_at":"2026-11-11T11:06:53.302002Z"}]}}