Description
InstantCMS is a free and open source content management system. Versions prior to 2.18.2 have a Server-Side Request Forgery (SSRF) vulnerability in the file upload functionality (`system/core/uploader.php` at lines 509-532). When the "upload from URL" feature follows an HTTP redirect, the redirected target URL bypasses the private IP address blacklist check. This allows authenticated users to scan and access internal network services. Version 2.18.2 contains a fix.
References3
Metrics
- CVSS 3.1
-
3.1
LOW
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 19 · as of 3 November 2026
- CWE
- CWE-918
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