CVE-2026-48707

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.

  • Published Sep 8, 2026
  • CVSS 3.1 low
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-48707 at the National Vulnerability Database