GitHub Advisoryadvisory · Packagist

GHSA-q9fm-mpg8-8jqm Concrete CMS is vulnerable to Stored XSS via page name in the Atomik theme

LOW Published 2026-05-26 Modified 2026-06-29 Official page ↗
Aliases
CVE-2026-8353
Ecosystem
Packagist
Packages
concrete5/concrete5
Severity
Low
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Weaknesses
CWE-79
Reviewed
2026-06-29

Affected packages

• Packagist concrete5/concrete5: >= 9.0.0RC.1, < 9.5.1 → fixed in 9.5.1

Description

Concrete CMS version 9.0 to 9.5.0 is vulnerable to Stored XSS via page name in the Atomik theme. A rogue editor can inject arbitrary JavaScript that executes in the context of any authenticated user visiting the affected account pages. This can lead to session hijacking, credential theft, malicious actions performed on behalf of users, and potential privilege escalation. Thanks Yonatan Drori (Tenzai) for reporting.

Related

Alias · CVE (1)

  • CVE-2026-8353 Concrete CMS version 9.0 to 9.5.0 is vulnerable to Stored XSS via page name in the Atomik theme. vulnerability

Weakness · CWE (1)

  • CWE-79 Improper Neutralization of Input During Web Page Generation weakness

References