Cyber Resilience

CVE-2026-40500

MediumPublic PoC

Published: 15 April 2026

Published
15 April 2026
Modified
01 May 2026
KEV Added
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Patch
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CVSS Score v4 6.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0039 30.3th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-40500 is a medium-severity SSRF (CWE-918) vulnerability in Processwire CMS (inferred from references). Its CVSS base score is 6.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Service Discovery (T1046); ranked at the 30.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)
CWE-918

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1046 Network Service Discovery Discovery
Adversaries may attempt to get a listing of services running on remote hosts and local network infrastructure devices, including those that may be vulnerable to remote software exploitation.
attack.mitre.org →
T1552.005 Cloud Instance Metadata API Credential Access
Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.
attack.mitre.org →
Why these techniques?

SSRF directly enables internal host/port scanning (T1046) and cloud metadata endpoint access (T1522) via outbound requests from the admin panel.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

Processwire
CMS
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-918

Penetration testing attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.

SC-7 Boundary Protection
addresses: CWE-918

Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.

SI-10 Information Input Validation
addresses: CWE-918

Validates server-side URLs and resource references to block SSRF attempts.

SI-4 System Monitoring
addresses: CWE-918

Detects server-side request forgery through monitoring of unexpected outbound connections.

References