CVE-2026-8421 - CERT CVE
ID CVE-2026-8421
Sažetak 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 reporting.
Reference
CVSS
Base: 0.0
Impact: None
Exploitability:None
Pristup
VektorSloženostAutentikacija
None None None
Impact
PovjerljivostCjelovitostDostupnost
None None None
CVSS vektor None
Zadnje važnije ažuriranje 21-05-2026 - 21:16
Objavljeno 21-05-2026 - 21:16