Vulnerability · Published May 21, 2026 · Assigned by ConcreteCMS
CVE-2026-6826Concrete 9.5.0 and below has file usage disclosure via missing permission check in Usage controller
Medium 6.9
In plain English
A medium-severity information exposure in Concrete CMS from Concrete CMS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.5% (higher than 74% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, Nuclei. Fixed versions are available - upgrade the affected package.
Official description
Concrete CMS 9.5.0 and below is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller. Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions.The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.9 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | concrete5/concrete5 | 9.5.1 | GHSA-4g7q-44qp-cc5c |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Concrete CMS | Concrete CMS | 5.0 – through 9.5.0 |
Weakness: CWE-200 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N