Description
Concrete CMS 9.5.0 and below is vulnerable to IDOR. The `/ccm/frontend/conversations/message_detail` 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. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Concrete CMS | Concrete CMS | — | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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aj2108/CVE-2026-8237 ★ 0 · Aug 1, 2026
CVE-2026-8237 is an Insecure Direct Object Reference (IDOR) vulnerability caused by missing authorization checks in Concrete CMS 9.5.0 and earlier.
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Automated scanner template
A ready-made Nuclei template detects this vulnerability automatically. Vulnerabilities with public scanner templates are typically probed across the internet soon after the template appears — exposed systems should be patched first.
- Concrete CMS <= 9.5.0 - Unauthenticated Conversation Message Disclosure (IDOR) http/cves/2026/CVE-2026-8237.yaml
Source: projectdiscovery/nuclei-templates (MIT) — updated daily. Only links are listed.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Packagist | concrete5/concrete5 | < 9.5.1 | 9.5.1 | GHSA-xpgc-7vc2-8725 |