Cloudanix VulnDB

CVE-2026-23744

Critical · 9.8

CVSS

9.8

EPSS

67.5%

Published

Jan 16, 2026

CISA due date

—

Cloudanix analysis

Act now SSVC: Attend

A development tool that helps build server components can be tricked over the network into running attacker code, potentially giving outsiders full control of developers' computers.

Weaponized
Exploitation
Remote Unauthenticated
Attacker needs
None
Complexity
Trivial
Impact
Remote Code Execution
Component
Application
Class
RCE
Remediation
Upgrade
Effort
Low
Patch risk
Low

What it actually does

The application binds to 0.0.0.0 and accepts unauthenticated HTTP requests that cause arbitrary MCP server installation and subsequent code execution.

Why it matters to the business

Attackers can fully compromise developer workstations and build systems from the network, leading to source-code theft, supply-chain tampering, and loss of development environment integrity; rising exploit likelihood increases urgency for organizations using this tool.

How an attack unfolds

An attacker sends a specially crafted HTTP request to the publicly reachable listener; the request triggers installation of a malicious MCP server that executes attacker-controlled code, providing remote access. The flaw has been weaponized and shows rapidly increasing exploitation probability.

How to fix it

Upgrade mcpjam/inspector to commit e6b9cf9d9e6c9cbec31493b1bdca3a1255fe3e7a or later; bind the listener explicitly to 127.0.0.1; disable remote access until patched.

How to confirm the fix worked

Verify the running version or commit hash matches the fixed commit; confirm the listener address is 127.0.0.1 in configuration; test that crafted install requests are rejected from remote hosts.

Typical attack path

  1. Discover reachable MCPJam inspector instance listening on all interfaces
  2. Craft and send malicious HTTP request that initiates MCP server installation
  3. Installed server executes attacker payload resulting in code execution
  4. Establish persistence or move laterally within the development environment

How to detect it

Review web server or application logs for unexpected HTTP requests that reference MCP server installation endpoints; look for new processes or files created after inbound HTTP traffic to the inspector port; correlate with unusual outbound connections from development hosts.

What your security team should do

  • Immediately upgrade all instances to the patched commit
  • Restrict network exposure by changing the bind address to localhost only
  • Monitor EPSS trend and threat intelligence for weaponized exploit availability
  • Scan development networks for any remaining unpatched instances

The record

MCPJam inspector is the local-first development platform for MCP servers. Versions 1.4.2 and earlier are vulnerable to remote code execution (RCE) vulnerability, which allows an attacker to send a crafted HTTP request that triggers the installation of an MCP server, leading to RCE. Since MCPJam inspector by default listens on 0.0.0.0 instead of 127.0.0.1, an attacker can trigger the RCE remotely via a simple HTTP request. Version 1.4.3 contains a patch.

Affected packages

Ecosystem Package Introduced Fixed
npm @mcpjam/inspector 0 1.4.3

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