{"id":"CVE-2026-81901","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-81901","generatedAt":"2026-10-28T02:57:27.145Z","title":"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…","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.","published":"2026-09-14T21:17:26.000Z","lastModified":"2026-09-18T19:17:29.000Z","status":"Analyzed","sourceIdentifier":"ff5b8ace-8b95-4078-9743-eac1ca5451de","cvss":{"version":"4.0","score":7.2,"severity":"HIGH","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/M"},"cwe":["CWE-862"],"affected":["concretecms/concrete cms"],"epss":{"score":0.00383,"percentile":0.32106,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes","tags":["Broken Link"],"source":"ff5b8ace-8b95-4078-9743-eac1ca5451de"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-81901","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}