CVE-2026-81911

Concrete CMS versions 9.0.0 through 9.5.2 contain a Stored XSS in the Board Custom Slot dialog. The custom_slot save_template endpoint authorizes requests only against the target board instance via canEditBoardContents() but persists the client-supplied selectedTemplateOption[collection] verbatim...

EUVD-2026-76447

Concrete CMS versions 9.0.0 to 9.5.2 is vulnerable to Stored XSS in Board Custom Slot dialog. The customslot savetemplate endpoint authorizes the request only against the target board instance canEditBoardContents and then persists the client-supplied selectedTemplateOptioncollection verbatim,...