{"id":"CVE-2026-7888","summary":"Concrete CMS below 9.5.2 is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components that lack the allowed_classes restriction.","details":"Concrete CMS below 9.5.2 is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components that lack the allowed_classes restriction. An unauthenticated attacker may trigger arbitrary PHP object instantiation if a malicious serialized payload has been placed in the database. Thanks XananasX7 and Sanjorn Keeratirungsan (dizconnect) for both independently reporting. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 8.4 with vector CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N.","modified":"2026-06-18T03:55:49.642842994Z","published":"2026-06-03T18:10:10.917Z","database_specific":{"cna_assigner":"ConcreteCMS","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/7xxx/CVE-2026-7888.json","cwe_ids":["CWE-502"]},"references":[{"type":"ADVISORY","url":"https://documentation.concretecms.org/9-x/developers/introduction/version-history/952-release-notes"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/7xxx/CVE-2026-7888.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-7888"},{"type":"PACKAGE","url":"https://github.com/concretecms/concretecms"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/concretecms/concretecms","events":[{"introduced":"0"},{"fixed":"8fe9708072c3815a5df719b592e4b23b43b4ff7a"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"5.0"},{"fixed":"9.5.2"}]}}],"versions":["9.5.1","9.5.0","9.5.0RC2","9.5.0RC1","9.4.4","9.4.3","9.4.2","9.4.1","9.4.0","9.4.0RC2","9.4.0RC1","9.3.7","9.3.6","9.3.5","9.3.0","9.3.4","9.3.3","9.3.2","9.3.1","8.4.1","8.3.1","8.2.1","8.2.0","8.2.0RC2","8.1.0","5.7.5.7","5.7.5.6","5.7.5.5","5.7.5.2","5.7.4.1","5.7.3.1","5.7.3","5.7.2.1","5.7.2","5.7.0.4","5.7.1","5.7.0.3","5.7.0.1","5.7.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-7888.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}