{"id":"CVE-2026-81902","summary":"Concrete CMS 9.0.0 to 9.5.2 is vulnerable to CSRF on Orphan Block Cleanup","details":"Concrete CMS 9 through 9.5.2 did not validate a CSRF token in the orphaned block removal panel action (removeOrphanedBlocks). A remote attacker could craft a request that, when loaded by an authenticated user holding edit permission on the target page, deleted every block on that page's current version; blocks not aliased to another page or scrapbook entry were also removed from the global Blocks table and their block-type data table, permanently destroying the content. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.1 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.","modified":"2026-09-17T03:30:29.128666017Z","published":"2026-09-14T20:34:23.837Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81902.json","cna_assigner":"ConcreteCMS","cwe_ids":["CWE-352"]},"references":[{"type":"ADVISORY","url":"https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81902.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-81902"},{"type":"PACKAGE","url":"https://github.com/concretecms/concretecms"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/concretecms/concretecms","events":[{"introduced":"b3774abddd475b4ba98b637402506f7a5ebd90ea"},{"last_affected":"8fe9708072c3815a5df719b592e4b23b43b4ff7a"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"9.0.0"},{"last_affected":"9.5.2"}]}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-81902.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"}]}