{"id":"CVE-2026-81912","title":"Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature","summary":"Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature. The dashboard/users/groups/bulkupdate/confirm() endpoint moved the selected group tree nodes without validating an action token, s…","severity":"medium","cvss":5.7,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","cwe":["CWE-352"],"vendor":"concretecms","product":"concrete_cms","affected":["concrete_cms < 9.5.4"],"patched":["concrete_cms 9.5.4"],"published":"2026-09-11","updated":"2026-09-24","sourceUpdated":"2026-09-24T20:18:47.767","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-81912","references":[{"url":"https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes","label":"ff5b8ace-8b95-4078-9743-eac1ca5451de"}],"tags":["nvd","cve.org"],"epss":0.00231,"epssPercentile":0.1236,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-11T19:36:20.590270Z"},"ingestedAt":"2026-09-14T00:35:28.533Z","slug":"CVE-2026-81912","body":"## Overview\n\nConcrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature. The dashboard/users/groups/bulkupdate/confirm() endpoint moved the selected group tree nodes without validating an action token, so a state-changing group move could be processed for an authenticated user who did not initiate it. Because relocating a group under a new parent causes that group's members to inherit the parent's permissions, a forged move can change effective authorization. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.7 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.\n\n## Affected\n\n- `concrete_cms < 9.5.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `concrete_cms 9.5.4`","depth":"sunlit","depthScore":31,"depthScoreParts":{"impact":31.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}