# CVE-2026-8327: Concrete CMS unverified password change and session bypass

Source: https://junglewise.ai/threats/cve-2026-8327-concrete-cms-unverified-password-change-and-session-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-21. Updated: 2026-06-24  
License: CC BY 4.0 with a link back

CVE-2026-8327 · Severity: medium · CVSS 4 · Published 2026-05-21

Concrete CMS, a popular content management system, contains a security flaw in how it handles user profile updates. This vulnerability allows a registered user to change their account password without providing their current one, and to disable security features designed to prevent account hijacking. This could allow an attacker who has gained limited access to a user's account to lock out the legitimate owner or bypass session protections.

Technologies: [Concrete CMS](https://junglewise.ai/threats/technologies/concrete-cms), [concrete5/concrete5 (Packagist)](https://junglewise.ai/threats/technologies/concrete5-concrete5). Vendors: [Concrete CMS](https://junglewise.ai/threats/vendors/concrete-cms), [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2026-8327 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-8327 being exploited in the wild.

**How severe is CVE-2026-8327?** Medium severity, with a CVSS score of 4, published 21 May 2026.

**Which products and versions are affected?** Concrete CMS <= 9.5.0, below 9.5.0; concrete5/concrete5 (Packagist) < 9.5.1, ECOSYSTEM:introduced=0,fixed=9.5.1.

**Is there a fix for CVE-2026-8327?** Yes. concrete5/concrete5 (Packagist): upgrade to 9.5.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-8327 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-8327?** Check whether you run Concrete CMS or concrete5/concrete5 (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- concrete5/concrete5 (Packagist): upgrade to 9.5.1 or later

  ```sh
  composer require concrete5/concrete5:^9.5.1
  ```


## Technical details

Concrete CMS 9.5.0 and below contains a vulnerability in the user-profile edit controller. The controller passes the entire raw POST array to the UserInfo::update() method without implementing field whitelisting (CWE-915). This allows an authenticated attacker to modify sensitive account attributes that should require re-authentication, such as changing a password without providing the current one (CWE-620). Additionally, attackers can manipulate the session validator to disable per-user IP-pinning, effectively bypassing session-hardening measures intended to detect and prevent session hijacking. The issue is addressed in version 9.5.1.

## Affected products

- Concrete CMS Concrete CMS <= 9.5.0

## Identifiers

- CVE-2026-8327
- GHSA-wmw3-3fv3-h54w

## Timeline

- 2026-05-21: disclosed: NVD Published Date
- 2026-05-22: advisory: GitHub Advisory published
- 2026-06-24: patched: Advisory reviewed and updated with patch information

## References

- [https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes](https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes)

## Related threats

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- [Concrete CMS unauthenticated Express entry search disclosure](https://junglewise.ai/threats/cve-2026-18120-concrete-cms-unauthenticated-express-entry-search-disclosure)
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