CVE-2026-81926 – Concrete CMS 9.4.0 through 9.5.2 did not escape colliding page paths before rendering them

Concrete CMS 9.4.0 through 9.5.2 did not escape colliding page paths before rendering them in the location panel’s duplicate-path confirmation dialog. The panel’s check endpoint returned the submitted path unmodified in its JSON response, and client-side JavaScript inserted each value into the dialog as raw HTML, so a crafted page path executed script in the editor’s authenticated browser session. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.