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 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.
History

Fri, 18 Sep 2026 15:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N'}


Tue, 15 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Concretecms
Concretecms concrete Cms
Vendors & Products Concretecms
Concretecms concrete Cms

Tue, 15 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 15 Sep 2026 18:45:00 +0000

Type Values Removed Values Added
Description 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 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.
Title Concrete CMS below 9.5.3 is vulnerable to Cross-Site Request Forgery (CSRF) in Block Arrangement Endpoint
Weaknesses CWE-352
References
Metrics cvssV4_0

{'score': 2.3, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: ConcreteCMS

Published: 2026-09-15T18:22:54.612Z

Updated: 2026-09-15T19:25:36.719Z

Reserved: 2026-08-27T18:23:01.366Z

Link: CVE-2026-81919

cve-icon Vulnrichment

Updated: 2026-09-15T19:25:26.299Z

cve-icon NVD

Status : Analyzed

Published: 2026-09-15T19:17:41.200

Modified: 2026-09-18T15:26:37.667

Link: CVE-2026-81919

cve-icon Redhat

No data.