Restricted-page disclosure via unchecked file usage requests
Published May 21, 2026 · Updated May 21, 2026
Information disclosure in Concrete CMS 9.5.0 and earlier allows remote attackers to obtain restricted-page references through a file ID. The usage controller accepts an arbitrary fID and returns every referencing page's ID, handle, and full URL without checking whether the requester can view those pages. No authentication or user interaction is required, but the response exposes page references rather than page contents or file contents.
Summary
What happened
Information disclosure in Concrete CMS 9.5.0 and earlier allows remote attackers to obtain restricted-page references through a file ID. The usage controller accepts an arbitrary fID and returns every referencing page's ID, handle, and full URL without checking whether the requester can view those pages. No authentication or user interaction is required, but the response exposes page references rather than page contents or file contents.
The record
- CVE
- CVE-2026-6826
- Published
- May 21, 2026
- Updated
- May 21, 2026
- Vendor
- Concrete CMS
- Product
- Concrete CMS
- Classifications
- CWE-200, T1213
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 21, 2026CVE publishedPublication date reported by the CVE source.
- May 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.0 <=9.5.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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