CVE-2026-81894CWE-79CWE-89cross-site-scriptingsql-injection

CVE-2026-81894

Medium · published September 15, 2026

CVSS v3.1
5.4
EPSS
0%
Percentile
13.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
8.5 · 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
EPSS
0.00237 · 13.9th percentile
Weaknesses
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'); CWE-89 · Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
Published
2026-09-15T21:17Z
Affected products (1)
ProductVersionsFixed in
concretecms/concrete_cms< 9.5.39.5.3
References (1)
https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes · ff5b8ace-8b95-4078-9743-eac1ca5451de
EPSS history
Timeline
  • 17 SEP 03:32Z
    EPSS moved — → 0%
    epss
  • 15 SEP 16:35Z
    Concrete CMS 9.5.2 and below is vulnerable to Stored DOM-based Cross-site Scripting (XSS) in the Gallery block image Caption field
    cvelistv5