{"id":"CVE-2026-8237","aliases":["GHSA-xpgc-7vc2-8725"],"url":"https://o3.security/vulnerability/CVE-2026-8237","summary":"Concrete CMS 9.5.0 and below is vulnerable to IDOR in the`/ccm/frontend/conversations/message_detail` endpoint","details":"Concrete CMS 9.5.0 and below is vulnerable to IDOR. The `/ccm/frontend/conversations/message_detail` endpoint returns the full content of any conversation message. An unauthenticated attacker can enumerate all conversation messages, including messages from restricted pages, member-only areas, and the moderation queue. File attachments with download URLs are also exposed. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.","published":"2026-05-21T21:01:37.990Z","modified":"2026-08-12T03:51:20.966643886Z","cvss":null,"epss":{"score":0.00201,"percentile":0.10357,"asOf":"2026-08-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"concrete5/concrete5","fixedVersion":"9.5.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8237.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8237"},{"type":"PACKAGE","url":"https://github.com/concretecms/concretecms"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:20.966643886Z"}}