---
id: CVE-2026-8237
title: "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"
summary: "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, incl…"
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-862
vendor: concretecms
product: concrete_cms
affected:
  - concrete_cms < 9.5.1
patched:
  - concrete_cms 9.5.1
published: '2026-05-21'
updated: '2026-07-23'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-8237'
references:
  - url: >-
      https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
    label: ff5b8ace-8b95-4078-9743-eac1ca5451de
tags:
  - nvd
  - exploit-available
epss: 0.0064
epssPercentile: 0.49297
ingestedAt: '2026-07-23T11:17:33.923Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/aj2108/CVE-2026-8237'
  nuclei:
    - CVE-2026-8237
  checkedAt: '2026-09-24T07:53:19.833Z'
exploitAvailable: true
---

## Overview

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

- `concrete_cms < 9.5.1`

## Remediation

Upgrade past the affected range:

- `concrete_cms 9.5.1`