CVE-2026-14540
Received Received - Intake

SSRF in Google mcp-toolbox via Unsafe HTTP Redirect

Publication date: 2026-07-31

Last updated on: 2026-07-31

Assigner: Google Inc.

Description
A Server-Side Request Forgery (SSRF) vulnerability exists in the generic HTTP source and tool components of Google mcp-toolbox versions 0.3.0 through 1.4.0. While the toolbox implements baseline input sanitization for user-controlled parameters, the underlying HTTP client (internal/sources/http/http.go) fails to safely regulate request redirection boundaries. Specifically, the client is initialized without a restrictive CheckRedirect policy hook and lacks target IP validation. An attacker or a malicious data-driven prompt can supply a crafted path parameter that triggers an open redirect or a direct destination swap on the target backend, coercing the mcp-toolbox into blindly following the redirection and making unauthorized requests to internal or arbitrary external endpoints.

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Meta Information

Published
2026-07-31
Last Modified
2026-07-31
Generated
2026-07-31
AI Q&A
2026-07-31
EPSS Evaluated
N/A
NVD
CVE-2026-14540
EUVD
EUVD-2026-51374

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
google mcp-toolbox From 0.3.0 (inc) to 1.4.0 (inc)

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.

Attack-Flow Graph

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Executive Summary

This is a Server-Side Request Forgery (SSRF) vulnerability in Google mcp-toolbox versions 0.3.0 through 1.4.0. The HTTP client component lacks proper redirection handling and target IP validation. Attackers can manipulate path parameters to force the toolbox into making unauthorized requests to internal or external endpoints by exploiting open redirects or destination swaps.

Detection Guidance

To detect this SSRF vulnerability in Google mcp-toolbox versions 0.3.0 through 1.4.0, inspect HTTP traffic logs for unexpected redirections or requests to internal/external endpoints. Check if the toolbox's HTTP client lacks a restrictive CheckRedirect policy or target IP validation. Use network monitoring tools like tcpdump or Wireshark to capture outbound requests from the mcp-toolbox process.

Impact Analysis

An attacker could exploit this to access internal systems, exfiltrate sensitive data, or make requests to arbitrary external servers. This may lead to data breaches, unauthorized actions on internal services, or network reconnaissance. Systems using vulnerable versions of mcp-toolbox are at risk if exposed to untrusted input.

Compliance Impact

This vulnerability could lead to unauthorized data access or exfiltration, violating GDPR's data protection principles or HIPAA's safeguards for protected health information. Organizations may face compliance violations, fines, or reputational damage if exploited. Proper mitigation is required to maintain regulatory adherence.

Mitigation Strategies

Upgrade Google mcp-toolbox to a version beyond 1.4.0 where the HTTP client includes a restrictive CheckRedirect policy and target IP validation. If upgrading is not immediately possible, implement network-level controls to block unauthorized outbound requests from the mcp-toolbox process.

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