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OS Command InjectionWeakness · CWE-78

CVE-2026-62312

HIGH · 8.8 CVSS v3.1 Published 2026-07-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click 5 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

9Router prior to 0.5.2 allows remote authenticated attackers to achieve arbitrary code execution by combining a Host header bypass of localhost-only routes with unvalidated MCP plugin arguments passed to child_process.spawn(), enabling malicious custom plugins to execute OS commands through the /api/mcp/<plugin>/sse endpoint.

MitigationUpgrade to version 0.5.2 or later, which implements validation for MCP plugin arguments to prevent command injection.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify 9Router version
    Check the installed 9Router version using the package manager, binary version flag, or examine the application binary/package metadata (e.g., rpm -q, dpkg -l, or 9router --version if available)
    Affected if Version is prior to 0.5.2 (e.g., 0.5.1, 0.5.0, or any pre-0.5.2 release)
  2. Confirm MCP plugin support is enabled
    Inspect the 9Router configuration files (typically in /etc/9router/, ~/.9router/, or a config directory) for MCP plugin-related settings, or check if the /api/mcp/ endpoints are exposed in the running service
    Affected if MCP plugin support is loaded or enabled in the configuration
  3. Verify network exposure of MCP endpoints
    Test if the /api/mcp/<plugin>/sse endpoint is reachable from non-localhost sources by sending an HTTP request with a manipulated Host header (e.g., Host: attacker-controlled-domain) to the 9Router service
    Affected if The endpoint responds to requests from non-loopback addresses or accepts arbitrary Host headers without rejecting them
  4. Check for custom MCP plugins installed
    List all installed MCP plugins in the plugin directory (commonly found under the 9Router installation path, such as /usr/lib/9router/plugins/, ./plugins/, or the configured plugin path)
    Affected if Any custom or third-party MCP plugins are present that were not verified as trusted or validated by the vendor
  5. Inspect MCP plugin argument handling
    Review the 9Router server logs or enable debug logging to observe how arguments are passed to child_process.spawn() when the /api/mcp/<plugin>/sse endpoint is invoked with crafted plugin arguments
    Affected if Arguments to the plugin are passed directly to spawn() without evident validation or sanitization in the request

You are affected if 9Router version is prior to 0.5.2, MCP plugin support is enabled, and the /api/mcp/<plugin>/sse endpoint is network-accessible (allowing Host header bypass) to trigger unvalidated argument injection into child_process.spawn().

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to version 0.5.2 or later, which implements validation for MCP plugin arguments to prevent command injection.

Recommended fix High confidence

0.5.2

  1. 1. Identify the current version of 9Router installed on the system
  2. 2. Upgrade 9Router to version 0.5.2 or later to address the OS command injection vulnerability

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-62312 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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