CVE-2026-81926: Concrete CMS 9.4.0 through 9.5.2 is vulnerable to Cross-site scripting in the location panel duplicate-path confirmation dialog
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 Software
Event History
Frequently Asked Questions
What access and conditions are required to exploit this issue?
The attacker needs high privileges and must cause a crafted page path to collide with an existing path. Exploitation also requires user interaction: an authenticated editor must open the duplicate-path confirmation dialog.
What is the impact if exploitation succeeds?
Script can execute in the authenticated editor's browser session. The supplied CVSS v4.0 vector indicates low impact to confidentiality, integrity, and availability within the vulnerable system.