CVE-2026-6826
mediumpriority · track · 32EPSS 0.015 · 73 %ileexploit · functionalEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (1)
Public proof-of-concept and weaponised exploit code.
affected products (3)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-4g7q-44qp-cc5cConcrete CMS is vulnerable to unauthenticated file usage disclosure2026-05-21ghsa · osvUS
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. Concrete CMS thanks Eldudareeno for reporting this issue.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (4)
External citations — patches, advisories, analysis.
- https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notesPatchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-6826cnnvd
- https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notesenisa_euvd
- https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notesRelease Notesnvd
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