🛡️ CVE-2026-8421
🟠 CVSS 8.8 — High ✅ No Known Exploit CWE-352 NVD
8.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Concrete CMS 9.5.0 and below contains a CSRF vulnerability in the install_package() method of concrete/controllers/single_page/dashboard/extend/install.php.  An attacker who can cause an authenticated administrator to visit a crafted page,  and who has placed or caused a package to be present under DIR_PACKAGES//, can force the installation of that package without any CSRF protection. Package installation executes the package controller's install() method as the web server user, enabling remote code execution.  In order to be vulnerable, the victim must be passing canInstallPackages. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks  https://github.com/maru1009  for reporting.

Details

Severity HIGH
CVSS Score 8.8
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE CWE-352
Public Exploit ✅ No
Source NVD
Published 2026-05-21
Updated 2026-06-02
Modified 2026-05-26
Fix URL N/A

Affected Packages

Software From version Fixed in
concrete-cms — 9.5.1
unknown — —

Similar Threats

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