VulnerabilityAnalyzed

CVE-2026-6826

Concrete CMS 9.5.0 and below is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.

MEDIUM 6.9EPSS 1.46%

Does this matter?

Lower severity and a low EPSS score (1.46%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 1.46% probability · 72th percentile
CISA KEV: Not listed
Weakness: CWE-200
Affected: concretecms/concrete cms
Source: ff5b8ace-8b95-4078-9743-eac1ca5451de

References

https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notesRelease Notes

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.