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.
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History
Tue, 15 Sep 2026 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Concrete CMS 9.5.2 and below is vulnerable to Stored DOM-based Cross-site Scripting (XSS) in the Gallery block image Caption field | |
| Weaknesses | CWE-89 | |
| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: ConcreteCMS
Published:
Updated: 2026-09-15T16:35:37.767Z
Reserved: 2026-08-27T18:18:39.736Z
Link: CVE-2026-81894
No data.
Status : Received
Published: 2026-09-15T17:17:27.543
Modified: 2026-09-15T17:17:27.543
Link: CVE-2026-81894
No data.
OpenCVE Enrichment
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Weaknesses