{"id":"CVE-2026-81919","title":"Concrete CMS below 9.5.3 did not validate an anti-CSRF token on the block-arrangement backend endpoint (the arrange() action of Concrete\\Controller\\Backend\\Page\\ArrangeBlocks)","summary":"Concrete CMS below 9.5.3 did not validate an anti-CSRF token on the block-arrangement backend endpoint (the arrange() action of Concrete\\Controller\\Backend\\Page\\ArrangeBlocks). The action enforced page-edit authorization but performed no…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","cwe":["CWE-352"],"vendor":"concretecms","product":"concrete_cms","affected":["concrete_cms < 9.5.3"],"patched":["concrete_cms 9.5.3"],"published":"2026-09-15","updated":"2026-09-18","sourceUpdated":"2026-09-18T15:26:37.667","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-81919","references":[{"url":"https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes","label":"ff5b8ace-8b95-4078-9743-eac1ca5451de"}],"tags":["nvd","cve.org","score-dispute"],"epss":0.00112,"epssPercentile":0.01569,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-15T19:25:21.786485Z"},"scores":{"nvd":4.3,"cna":2.3},"ingestedAt":"2026-09-15T18:41:59.180Z","slug":"CVE-2026-81919","body":"## Overview\n\nConcrete CMS below 9.5.3 did not validate an anti-CSRF token on the block-arrangement backend endpoint (the arrange() action of Concrete\\Controller\\Backend\\Page\\ArrangeBlocks). The action enforced page-edit authorization but performed no token check, and its route accepted any HTTP method, so an attacker could induce a signed-in content editor into loading an attacker-controlled page that auto-submitted a cross-site request and reordered or moved blocks in the draft version of a page the victim was permitted to edit. The default null cookie SameSite configuration let the victim's session cookie accompany the forged request. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.\n\n## Affected\n\n- `concrete_cms < 9.5.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `concrete_cms 9.5.3`","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":206893,"id":"CVE-2026-81919","ts":1789746311948,"field":"cvss","old":"2.3","new":"4.3"},{"seq":206892,"id":"CVE-2026-81919","ts":1789746311948,"field":"severity","old":"low","new":"medium"}]}