CVE-2026-8417CWE-352

Concrete CMS 9.5.0 and below is vulnerable to CSRF in do_update() in the package update controller

High · published May 21, 2026

CVSS v4.0
7.5
EPSS
0%
Percentile
7.9
In the wild
Unconfirmed
What it is

Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/update/do_update/<pkgHandle>. The do_update() method in concrete/controllers/single_page/dashboard/extend/update.php checks only canInstallPackages() before executing upgradeCoreData() and upgrade() on the named package's controller. Because the endpoint is a state-changing GET route with no token enforcement, an attacker can force an authenticated administrator to trigger a package upgrade via a single cross-site navigation.In order to be vulnerable, the victim must be passing canInstallPackages() and and a target package must already be already installed. 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.

The record
Technical detail
CVSS v4.0
7.5 · HIGH
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
EPSS
0.00187 · 7.9th percentile
Weakness
CWE-352 · Cross-Site Request Forgery (CSRF)
Published
2026-05-21T20:19Z
EPSS history
Timeline
  • 21 MAY 20:19Z
    Concrete CMS 9.5.0 and below is vulnerable to CSRF in do_update() in the package update controller
    cvelistv5