Concrete CMS up to 9.5.0 download cross-site request forgery

Summaryinfo

A vulnerability was found in Concrete CMS up to 9.5.0 and classified as problematic. This vulnerability affects the function Download of the file /dashboard/extend/install/download/. The manipulation results in cross-site request forgery. This vulnerability is reported as CVE-2026-8140. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Concrete CMS up to 9.5.0. It has been classified as problematic. Affected is the function download of the file /dashboard/extend/install/download/. The manipulation with an unknown input leads to a cross-site request forgery vulnerability. CWE is classifying the issue as CWE-352. The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request. This is going to have an impact on integrity. CVE summarizes:

Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/install/download/<remoteId>. The download() method in concrete/controllers/single_page/dashboard/extend/install.php checks only the canInstallPackages() permission before fetching a remote marketplace package and writing it to the server's DIR_PACKAGES directory. Because the endpoint is a state-changing GET route with no token enforcement, an attacker who can cause an authenticated administrator to visit a crafted page can force an arbitrary marketplace package to be downloaded. In order to be vulnerable, the victim must be passing canInstallPackages() and the site must be connected to the Concrete marketplace. 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 advisory is available at documentation.concretecms.org. This vulnerability is traded as CVE-2026-8140 since 05/07/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Content Management System

Vendor

• Concrete

Name

• CMS

Version

• 9.0
• 9.1
• 9.2
• 9.3
• 9.4
• 9.5.0

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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