CVE-2026-40500
Received Received - Intake
Server-Side Request Forgery in ProcessWire CMS Admin Module

Publication date: 2026-04-15

Last updated on: 2026-04-15

Assigner: VulnCheck

Description
ProcessWire CMS version 3.0.255 and prior contain a server-side request forgery vulnerability in the admin panel's 'Add Module From URL' feature that allows authenticated administrators to supply arbitrary URLs to the module download parameter, causing the server to issue outbound HTTP requests to attacker-controlled internal or external hosts. Attackers can exploit differentiable error messages returned by the server to perform reliable internal network port scanning, host enumeration across RFC-1918 ranges, and potential access to cloud instance metadata endpoints.
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Meta Information
Published
2026-04-15
Last Modified
2026-04-15
Generated
2026-06-16
AI Q&A
2026-04-16
EPSS Evaluated
2026-06-15
NVD
CVE-2026-40500
EUVD
EUVD-2026-23121
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
processwire processwire to 3.0.256 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-918 The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
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Executive Summary

This vulnerability exists in ProcessWire CMS version 3.0.255 and earlier. It is a server-side request forgery (SSRF) issue found in the admin panel's 'Add Module From URL' feature. Authenticated administrators can provide arbitrary URLs to the module download parameter, which causes the server to make outbound HTTP requests to attacker-controlled internal or external hosts.

Attackers can exploit this behavior to perform internal network reconnaissance, such as port scanning and host enumeration within private IP ranges (RFC-1918). They may also gain potential access to sensitive cloud instance metadata endpoints by analyzing the different error messages returned by the server.

Impact Analysis

The vulnerability can allow attackers to conduct internal network port scanning and host enumeration, which can reveal sensitive network infrastructure details.

It may also enable attackers to access cloud instance metadata endpoints, potentially exposing sensitive configuration or credential information.

Since the vulnerability requires authenticated administrator access, the impact depends on the level of trust and security of administrator accounts.

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