Vulnerability · Published Sep 11, 2026 · Assigned by ConcreteCMS
CVE-2026-68526Concrete CMS before 9.5.3 is vulnerable to CSRF in the Calendar event duplicate dialog controller
Medium 5.3
In plain English
A medium-severity cross-site request forgery in Concrete CMS from Concrete CMS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities).
Official description
Concrete CMS before 9.5.3 did not validate an anti-CSRF token in the Calendar event duplicate dialog controller (concrete/controllers/dialog/event/duplicate.php) submit() action, which duplicated a calendar event after checking only canAccess() and the per-resource canAddCalendarEvent() permission, so a crafted cross-site request could cause an authenticated user with add-event permission to create duplicate CalendarEvents and CalendarEventVersions records under their own authority. 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Concrete CMS | Concrete CMS | 9.5.2 |
Weakness: CWE-352 · 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