Concrete CMS up to 9.5.0 bulk_user_assignment.php authorization

Summaryinfo

A vulnerability has been found in Concrete CMS up to 9.5.0 and classified as problematic. This affects an unknown part of the file bulk_user_assignment.php. The manipulation leads to authorization. This vulnerability is documented as CVE-2026-8350. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Concrete CMS up to 9.5.0 and classified as problematic. This issue affects an unknown part of the file bulk_user_assignment.php. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-863. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation to Administrative Group. Any authenticated user with access to the bulk user assignment dashboard page can add any user email to any group and can remove legitimate admins. 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:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Vincent55 for reporting.

The weakness was released by Vincent55. The advisory is shared at documentation.concretecms.org. The identification of this vulnerability is CVE-2026-8350 since 05/11/2026. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation needs additional levels of successful authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/22/2026).

By approaching the search of inurl:bulk_user_assignment.php it is possible to find vulnerable targets with Google Hacking.

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

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-31343). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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