CVE-2026-6826Concrete 9.5.0 and below has file usage disclosure via missing permission check in Usage controller
- 6.9MediumCVSS base score
- 1.5%Exploitation in 30 daysEPSS · top 26% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- 2Public exploitsMetasploit, Nuclei and Exploit-DB
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Metasploit module and a Nuclei template for it.
Show the exploits2
Metasploit modules1 module
- Concrete CMS Unauthenticated File Usage Disclosure (Metasploit module) (opens in a new tab)
auxiliary/scanner/http/concrete_cms_file_usage_disclosureRank normaldisclosed 21 May 2026
Nuclei templates1 template
- Concrete CMS <9.5.1 - Unauthenticated File Usage Disclosure (Nuclei template) (opens in a new tab)
http/cves/2026/CVE-2026-6826.yamlSeverity medium
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By ConcreteCMS
- 30 days later
· 30 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ConcreteCMSCNA (assigner) | 4.0 | Medium6.9 | 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 |
| NVDNVD · Analyzed | 4.0 | Medium6.9 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 1.5% · top 26% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.9.
Affected products
- affected 5.0 – ≤ 9.5.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Packagistconcrete5/concrete5GHSA-4g7q-44qp-cc5c (opens in a new tab)
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-31344 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-4g7q-44qp-cc5c (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-6826)Record last updated .