CVE-2026-81894
EUVD-2026-7883315.09.2026, 17:17
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.
Affected Products (NVD)
| Vendor | Product | Version |
|---|---|---|
| concretecms | concrete_cms | 𝑥 < 9.5.3 |
𝑥
= Vulnerable software versions
Common Weakness Enumeration
- CWE-89 - Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.