CVE-2026-8417 HIGH

CVE-2026-8417: Concrete CMS 9.5.0 and below is vulnerable to CSRF in do_update() in the package update controller

Vendor Concrete Cms
Product Concrete CMS
Weakness CWE-352 · CSRF
Published May 21, 2026
Last update May 22, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction
Confidentiality
Integrity

CVSS 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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 21, 2026 CVE published
May 22, 2026 Record updated

Related vulnerabilities

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