Description
In Concrete CMS 9.0 to 9.5.2, the Top Navigation Bar block did not HTML-escape dropdown child page names before writing them into the page, so a user who could create or rename pages could store a script through a child page name and have it run in the browser of any visitor, editor, or administrator who viewed the navigation and opened the affected dropdown. In the Concrete CMS origin, the script executed with the victim's privileges and could read same-origin content or perform actions available to that user. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks labixiaoxin97 for reporting.
Published: 2026-09-15
Score: 7.5 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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History

Tue, 15 Sep 2026 17:45:00 +0000

Type Values Removed Values Added
Description In Concrete CMS 9.0 to 9.5.2, the Top Navigation Bar block did not HTML-escape dropdown child page names before writing them into the page, so a user who could create or rename pages could store a script through a child page name and have it run in the browser of any visitor, editor, or administrator who viewed the navigation and opened the affected dropdown. In the Concrete CMS origin, the script executed with the victim's privileges and could read same-origin content or perform actions available to that user. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks labixiaoxin97 for reporting.
Title Concrete CMS 9.0 to 9.5.2 is vulnerable to Stored XSS in the Top Navigation Bar Block via Dropdown Child Page Names
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 7.5, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: ConcreteCMS

Published:

Updated: 2026-09-15T17:32:16.023Z

Reserved: 2026-07-28T18:01:57.257Z

Link: CVE-2026-18113

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-15T18:17:17.770

Modified: 2026-09-15T18:17:17.770

Link: CVE-2026-18113

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-79

    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')