# CVE-2026-8347: Concrete CMS IDOR in Express association Reorder dialog

Source: https://junglewise.ai/threats/cve-2026-8347-concrete-cms-idor-in-express-association-reorder-dialog  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-22. Updated: 2026-07-23  
License: CC BY 4.0 with a link back

CVE-2026-8347 · Severity: medium · CVSS 4.3 · Published 2026-05-22

Concrete CMS is a content management system used to build and manage websites. A security flaw in the 'Express' data management component allows a user with limited 'view-only' permissions to change the display order of data entries. This could allow an unauthorized user to manipulate how information is presented to others, potentially disrupting business workflows or data organization.

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-2026-8347 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-8347 being exploited in the wild.

**How severe is CVE-2026-8347?** Medium severity, with a CVSS score of 4.3, published 22 May 2026.

**Which products and versions are affected?** Concrete CMS <= 9.5.0, 5.0 to 9.5.0; concrete5/concrete5 (Packagist) < 9.5.1, ECOSYSTEM:introduced=0,fixed=9.5.1.

**Is there a fix for CVE-2026-8347?** 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-2026-8347 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-8347?** 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 versions 9.5.0 and below contain an Insecure Direct Object Reference (IDOR) and improper authorization level check within the Express association Reorder dialog. An authenticated attacker with low-level 'view-only' permissions can exploit this flaw to reorder Express entities, a task that should require higher administrative privileges. This results in cross-entity state tampering. The vulnerability specifically affects sites utilizing the Express component and relying on entity ordering. The issue is addressed in version 9.5.1.

## Affected products

- Concrete CMS Concrete CMS 5.0 to 9.5.0

## Identifiers

- CVE-2026-8347
- GHSA-jqvq-gv67-3567

## Timeline

- 2026-05-22: advisory: NVD and Vendor advisory published
- 2026-05-22: patched: Fixed in version 9.5.1 release notes

## References

- [https://github.com/concretecms/concretecms](https://github.com/concretecms/concretecms)
- [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

- [Concrete CMS OAuth REST API authorization bypass](https://junglewise.ai/threats/cve-2026-85387-concrete-cms-oauth-rest-api-authorization-bypass)
- [Concrete CMS unauthenticated Express entry search disclosure](https://junglewise.ai/threats/cve-2026-18120-concrete-cms-unauthenticated-express-entry-search-disclosure)
- [Concrete CMS REST API user creation permission bypass](https://junglewise.ai/threats/cve-2026-87031-concrete-cms-rest-api-user-creation-permission-bypass)
- [Concrete CMS access control bypass in board custom-slot preview](https://junglewise.ai/threats/cve-2026-87028-concrete-cms-access-control-bypass-in-board-custom-slot-preview)
- [Concrete CMS stored XSS via XML file upload in Form Block](https://junglewise.ai/threats/cve-2026-85386-concrete-cms-stored-xss-via-xml-file-upload-in-form-block)