CVE-2026-48707

InstantCMS vulnerable to SSRF via upload redirect bypass allows internal network service scanning

Published Sep 8, 2026 CVSS 3.1 · 3.1 Low EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Instantcms
Instantcms icms2
Vendors & Products Instantcms
Instantcms icms2
Type Values Removed Values Added
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.
Title InstantCMS vulnerable to SSRF via upload redirect bypass allows internal network service scanning
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 3.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 11, 2026, 8:51 PM
Reserved
May 22, 2026, 6:47 PM
Status
Deferred
Published
Sep 8, 2026, 6:17 PM
Modified
Sep 11, 2026, 9:17 PM