CVE-2026-62312

Deferred Deferred - Pending Action

Remote Code Execution in 9Router AI Router

Publication date: 2026-07-15

Last updated on: 2026-07-16

Assigner: GitHub, Inc.

Description

9Router is an AI router & token saver. Prior to 0.5.2, 9Router allows a remote authenticated attacker to achieve arbitrary code execution on the host operating system by combining a Host header bypass of localhost-only routes with unvalidated MCP plugin args passed to child_process.spawn(), allowing malicious custom plugins to execute commands through /api/mcp//sse. This issue is fixed in version 0.5.2.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-15

Last Modified

2026-07-16

Generated

2026-08-05

AI Q&A

2026-07-16

EPSS Evaluated

2026-08-03

NVD

CVE-2026-62312

Affected Vendors & Products

Vendor	Product	Version / Range
9router	9router	0.5.2

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-78	The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

Attack-Flow Graph

Executive Summary

This vulnerability affects 9Router versions prior to 0.5.2. A remote authenticated attacker can bypass localhost-only route restrictions using a Host header manipulation technique. They can then pass unvalidated MCP plugin arguments to child_process.spawn(), enabling arbitrary command execution on the host operating system through the /api/mcp//sse endpoint.

Detection Guidance

To detect this vulnerability, check if your 9Router version is below 0.5.2. If so, it is vulnerable. No specific commands are provided in the context, but you can verify the version via the admin interface or logs.

Impact Analysis

If exploited, this vulnerability allows attackers to execute arbitrary commands on the system running 9Router. This could lead to full system compromise, data theft, unauthorized access, or disruption of services. Attackers need valid authentication credentials to exploit this issue.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR and HIPAA requirements for data protection and access controls. Organizations using affected versions may face compliance violations, legal penalties, and reputational damage.

Mitigation Strategies

Update 9Router to version 0.5.2 or later to address the vulnerability. Disable or remove any untrusted custom MCP plugins that may allow command execution. Restrict network access to the /api/mcp//sse endpoint to prevent unauthorized access.

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