TI-2026-05987 Aliases CVE-2026-6826 GHSA-4g7q-44qp-cc5c

Concrete 9.5.0 and below has file usage disclosure via missing permission check in Usage controller

LOW 39CWE-200Published 2026-05-21 · Updated 2026-05-22

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Information disclosure
Confidentiality · integrity · availability: Low · None · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-200.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.01461 73rd percentileScored 2026-11-07

Fix Fixed concrete5/concrete5 (Packagist): 9.5.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	concrete5/concrete5 (Packagist)	before 9.5.1	9.5.1	Patch available	GHSA-4g7q-44qp-cc5c

concrete5/concrete5 (Packagist) Vendor— Affected before 9.5.1 Fixed in 9.5.1 Patch available GHSA-4g7q-44qp-cc5c

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:concretecms:concrete_cms::::::::	before 9.5.1	Vulnerable	Concrete CMS

cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:* Versions before 9.5.1 Vulnerable ·Concrete CMS

Remediation

Fix · GHSA-4g7q-44qp-cc5c concrete5/concrete5 (Packagist) Fixed in 9.5.1 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-6826
2026-10-03 Alias added: GHSA-4g7q-44qp-cc5c

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-6826

Other 2

TI-2026-23602 ConcreteCMS v9.4.7 contains a Denial of Service (DoS) vulnerability in the File Manager… CVSS 3.1MEDIUM 6.5
TI-2023-23992 A Cross Site Scripting (XSS) vulnerability in Concrete CMS from versions 9.2.0 to 9.2.2… CVSS 3.1MEDIUM 5.4
TI-2023-26495 Concrete CMS before 8.5.13 and 9.x before 9.2.2 allows unauthorized access because… CVSS 3.1CRITICAL 9.8
TI-2026-14907 Missing authorization in Concrete CMS CVSS 4.0HIGH 8.7
TI-2022-06200 Cleartext transmission of sensitive information in https://github.com/concrete5/concrete5 CVSS 3.1CRITICAL 9.8
TI-2021-17294 An issue was discovered in Concrete CMS through 8.5.5. CVSS 3.1CRITICAL 9.8

See all 197 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences