Reflected XSS in Concrete CMS via Legacy Pagination

Publication date: 2026-05-21

Last updated on: 2026-05-26

Assigner: ConcreteCMS

Description

Concrete CMS 9.5.0 and below is vulnerable to Reflected XSS in Legacy Pagination via HTML attribute injection. Concrete\Core\Legacy\Pagination builds pagination links by raw-interpolating its $URL field into href="" (<a href="{$linkURL}" …>). Any authenticated admin or report viewer with access to `/dashboard/reports/forms/legacy` who clicks the crafted URL fires the payload in their session. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.0 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori (Tenzai) for reporting

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-05-21

Last Modified

2026-05-26

Generated

2026-07-02

AI Q&A

2026-05-22

EPSS Evaluated

2026-06-30

NVD

CVE-2026-8245

EUVD

EUVD-2026-31357

Affected Vendors & Products

Vendor	Product	Version / Range
concretecms	concrete_cms	to 9.5.1 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-83	The product does not neutralize or incorrectly neutralizes "javascript:" or other URIs from dangerous attributes within tags, such as onmouseover, onload, onerror, or style.

Attack-Flow Graph

Executive Summary

This vulnerability affects Concrete CMS version 9.5.0 and below. It is a Reflected Cross-Site Scripting (XSS) issue occurring in the Legacy Pagination feature through HTML attribute injection. Specifically, the system builds pagination links by directly inserting a URL field into the href attribute of anchor tags without proper sanitization. As a result, an authenticated admin or report viewer who accesses the affected dashboard page and clicks on a specially crafted URL can trigger the malicious payload within their session.

Impact Analysis

The vulnerability can lead to the execution of malicious scripts in the context of an authenticated user's session. This can result in unauthorized actions being performed on behalf of the user, session hijacking, or theft of sensitive information accessible to the user. Since the attack requires an authenticated admin or report viewer to click a crafted link, it can compromise administrative functions or sensitive report data within the Concrete CMS environment.

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