CVE-2026-81926: Concretecms Concrete CMS

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Concretecms Concrete CMS: from 9.4.0, before 9.5.3 (fixed in 9.5.3)

Published 2026-09-15. Last modified 2026-09-21.