What is GHSA-qv3x-mffx-9gw8?

GHSA-qv3x-mffx-9gw8 is a security advisory published by GitHub Security Advisories with Medium severity. Concrete CMS is vulnerable to IDOR

Which CVE IDs does GHSA-qv3x-mffx-9gw8 cover?

GHSA-qv3x-mffx-9gw8 covers the following CVE IDs: CVE-2026-8238. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

Which products are affected by GHSA-qv3x-mffx-9gw8?

GHSA-qv3x-mffx-9gw8 affects 1 product, including: composer/concrete5/concrete5:\u003c 9.5.1.

GHSA-qv3x-mffx-9gw8Medium

Concrete CMS is vulnerable to IDOR

Vendor

GitHub Security Advisories

Published

May 22, 2026

Last Modified

June 24, 2026

🔗 CVE IDs covered (1)

CVE-2026-8238 →

📋 Description

Concrete CMS 9.5.0 and below is vulnerable to IDOR. The '/ccm/frontend/conversations/message_page' endpoint returns the full content of any conversation message. An unauthenticated attacker can enumerate all conversation messages, including messages from restricted pages, member-only areas, and the moderation queue. File attachments with download URLs are also exposed.

🎯 Affected products1

composer/concrete5/concrete5:< 9.5.1

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2026-8238
https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
https://github.com/advisories/GHSA-qv3x-mffx-9gw8