CVE-2026-8327 Concrete CMS has a session-hardening bypass and allows password change without reauthorization
Attackers can change user passwords without reauthorization and disable session IP pinning, potentially leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-8327?
CVE-2026-8327 is a medium-severity missing authorization vulnerability in Concretecms Concrete Cms, published on 21 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Concrete CMS below 9.5.0 and below is vulnerable to password change without reauthorization and session-hardening bypass. The user-profile edit controller passes the entire raw POST array to UserInfo::update() without field whitelisting resulting in password change without requiring the current password and also resulting in registered users able to disable the per-user-IP-pinning in the session validator which is meant to detect hijacking. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 5.3 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks 0x4c616e for reporting.
Which versions are affected by CVE-2026-8327?
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-2026-8327?
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-2026-8327 being exploited?
There is no known exploitation of CVE-2026-8327 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-wmw3-3fv3-h54w.