CVE-2026-84432 Details
Description
Concrete CMS 9 through 9.5.2 did not validate an anti-CSRF token in the Boards custom slot dialog controller (concrete/controllers/dialog/board/custom_slot.php) saveTemplate() action. The action created a board_slot_proxy Block and dispatched an AddCustomSlotToBoardCommand against a board instance while gating only on the per-resource canEditBoardContents() permission, so a crafted cross-site request could cause a user holding board-edit permission with an active session to write attacker-chosen slot and template data to a board under their own authority. The state-changing database write completed before any downstream rendering, so the forged request succeeded even when the HTTP response returned a non-200 status. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.3 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.
A cross-site request forgery (CSRF) vulnerability has been identified in Concrete CMS versions 9.0.0 through 9.5.2. The issue arises in the Boards custom slot dialog controller, specifically within the saveTemplate() action. This action fails to properly validate anti-CSRF tokens, allowing a user with board-edit permissions and an active session to unintentionally add custom slot and template data to a board. The vulnerability exploits the fact that the database write occurs before any rendering, enabling the forged request to succeed even if the HTTP response indicates an error.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 10, 2026CISA-ADP
Assessed Sep 10, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes | ConcreteCMS | Broken LinkVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-352 | Cross-Site Request Forgery (CSRF) | ConcreteCMS |
Affected Products
| Product | Versions |
|---|---|
| Concrete CMS | >= 9, <= 9.5.2 |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 10, 2026 | New CVE Received | ConcreteCMS |
| Sep 10, 2026 | CVE Modified | CISA-ADP |