Internal network access via unchecked redirect targets
Published Sep 8, 2026 · Updated Sep 8, 2026
SSRF in InstantCMS before 2.18.2 allows remote authenticated users to scan and access internal network services through file uploads. The uploadFromLink() redirect path in system/core/uploader.php recursively fetches a Location target without repeating the private or reserved IP check. Access requires an authenticated account with the upload-from-URL feature, and responses expose internal service reachability or content.
Summary
What happened
SSRF in InstantCMS before 2.18.2 allows remote authenticated users to scan and access internal network services through file uploads. The uploadFromLink() redirect path in system/core/uploader.php recursively fetches a Location target without repeating the private or reserved IP check. Access requires an authenticated account with the upload-from-URL feature, and responses expose internal service reachability or content.
The record
- CVE
- CVE-2026-48707
- Published
- Sep 8, 2026
- Updated
- Sep 8, 2026
- Vendor
- InstantCMS Team
- Product
- InstantCMS
- Classifications
- CWE-918, CAPEC-664, T1046
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 8, 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=< 2.18.2
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upload redirect SSRF proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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