CVE-2026-8239 - Concrete CMS 9.5.0 and below is vulnerable to IDOR in '/ccm/frontend/conversations/get_rating'

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MEDIUM

Concrete CMS 9.5.0 and below is vulnerable to IDOR in '/ccm/frontend/conversations/get_rating'

Published May 21, 2026

6.3

MEDIUM

CVSS 4.0

EPSS 0.33%

Description

Concrete CMS 9.5.0 and below is vulnerable to IDOR. The '/ccm/frontend/conversations/get_rating' endpoint confirms existence and returns rating score for any message by ID. 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 Tristan Madani for reporting.

Affected products

Vendor Concrete CMS Product Concrete CMS Default
unaffected
- Version
  5.0
  Status
  affected
  Constraints
  <=9.5.0

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor

Product

Default status

Versions

Concrete CMS

unaffected

Version	Status	Constraints
5.0	affected	<=9.5.0

Remediation

No remediation recorded yet.

Weaknesses (1)

CWE-862

Missing Authorization

References (3)

https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
release-notesRelease Notes
https://github.com/advisories/GHSA-2xp7-rpvc-pjwc
Advisory
https://nvd.nist.gov/vuln/detail/CVE-2026-8239

Link	Providers	Tags
https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes		release-notesRelease Notes
https://github.com/advisories/GHSA-2xp7-rpvc-pjwc		Advisory
https://nvd.nist.gov/vuln/detail/CVE-2026-8239