Internal resource disclosure via cross-port DNS pin reuse
Published Sep 15, 2026 · Updated Sep 15, 2026
SSRF in Concrete CMS 9.0.0 through 9.5.2 allows remote authenticated users to save internal resource responses through remote file import. The importer retains only the first ValidatedRemoteUrl for a host and reuses it across later URLs on different ports, leaving the later download outside the original DNS pin. Exploitation requires file-import permission and control of a rebinding hostname; the server can read loopback, private-network, or cloud-metadata resources and store their responses.
Summary
What happened
SSRF in Concrete CMS 9.0.0 through 9.5.2 allows remote authenticated users to save internal resource responses through remote file import. The importer retains only the first ValidatedRemoteUrl for a host and reuses it across later URLs on different ports, leaving the later download outside the original DNS pin. Exploitation requires file-import permission and control of a rebinding hostname; the server can read loopback, private-network, or cloud-metadata resources and store their responses.
The record
- CVE
- CVE-2026-18424
- Published
- Sep 15, 2026
- Updated
- Sep 15, 2026
- Vendor
- Concrete CMS
- Product
- Concrete CMS
- Classifications
- T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 15, 2026CVE publishedPublication date reported by the CVE source.
- Sep 15, 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=9.0.0 <=9.5.2
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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