cvedb.io
CVE-2026-8421
HIGH · CVSS 8.8
EPSS exploitation probability: 0%
Published 2026-05-21T21:16:34.107 · Last modified 2026-06-17T11:03:55.123

Summary

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/<handle>/, 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 re

Affected products

concretecms — concrete_cms

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.