CVE-2026-8417
Analyzed Analyzed - Analysis Complete
CSRF in Concrete CMS Package Update

Publication date: 2026-05-21

Last updated on: 2026-05-26

Assigner: ConcreteCMS

Description
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.
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Meta Information
Published
2026-05-21
Last Modified
2026-05-26
Generated
2026-06-11
AI Q&A
2026-05-22
EPSS Evaluated
2026-06-10
NVD
CVE-2026-8417
EUVD
EUVD-2026-31334
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
concretecms concrete_cms to 9.5.1 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-352 The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.
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Executive Summary

This vulnerability affects Concrete CMS version 9.5.0 and below. It occurs because the system does not validate a CSRF (Cross-Site Request Forgery) token before processing requests to the /dashboard/extend/update/do_update/&lt;pkgHandle&gt; endpoint.

The do_update() method checks only if the user can install packages (canInstallPackages()) before executing upgradeCoreData() and upgrade() on the specified package's controller. Since this endpoint is a state-changing GET route without token enforcement, an attacker can trick an authenticated administrator into triggering a package upgrade simply by making them visit a malicious link.

For the attack to succeed, the victim must have permission to install packages and the targeted package must already be installed.

Impact Analysis

This vulnerability can allow an attacker to force an authenticated administrator to unknowingly upgrade a package. This could lead to unauthorized changes in the system, potentially introducing malicious code or destabilizing the CMS.

Because the attack exploits a state-changing GET request without proper CSRF protection, it can be triggered via a single cross-site navigation, making it easier for attackers to exploit.

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