CVE-2026-8350 Concrete CMS is vulnerable to missing authorization in the bulk_user_assignment.php
Authenticated users can escalate privileges to Administrative Group by adding or removing users from groups via the bulk user assignment page.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-8350?
CVE-2026-8350 is a high-severity missing authorization vulnerability in Concretecms Concrete Cms, published on 21 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
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.
Weakness: CWE-863
Which versions are affected by CVE-2026-8350?
2 open source packages ship an affected version, including concrete5/concrete5. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
concrete5/concrete5 Packagist | All versions | 9.5.1 |
concrete5/concrete5 Packagist | All versions | 9.5.1 |
Products include Concretecms Concrete Cms.
How do I fix CVE-2026-8350?
Upgrade concrete5/concrete5 to 9.5.1 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-8350 being exploited?
There is no known exploitation of CVE-2026-8350 in the wild and no public exploit code.
Other vulnerabilities in Concretecms Concrete Cms
- CVE-2023-48648 Concrete CMS allows unauthorized access because directories can be created with insecure permissions
- CVE-2022-21829 Code injection in concrete CMS
- CVE-2021-22958 Server-Side Request Forgery vulnerability in concrete5
- CVE-2021-40098 Path traversal in n/a
- CVE-2026-8134 Concrete CMS Vulnerable to Relative Path Traversal
Sources
Also known as GHSA-g7xp-jf3x-wcx4.