Concrete CMS 9.5.2 and below is vulnerable to stored DOM-based Cross-site Scripting (XSS) via the Gallery block's per-image Caption field because the bundled Magnific Popup lightbox script (concrete/js/features/imagery/frontend.js) re-parses the attribute-decoded caption as HTML through jQuery's .append() in titleSrc instead of inserting it as text. A user with permission to edit a page containing a Gallery block can store a caption that executes in the browser of any visitor who opens that image's lightbox. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 8.5 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Yonatan Drori (Tenzai) for reporting.
CVSS
No CVSS.
References
Configurations
No configuration.
History
No history.
Information
Published : 2026-09-15 17:17
Updated : 2026-09-15 17:17
NVD link : CVE-2026-81894
Mitre link : CVE-2026-81894
CVE.ORG link : CVE-2026-81894
JSON object : View
Products Affected
No product.
CWE
CWE-89
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
