InspectorApplication · Mcpjam

CVE-2026-23744

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-16
Fix available
A fix is available. Upgrade to 1.4.3 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click Patch available

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
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.

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

MCPJam inspector versions 1.4.2 and earlier contain an RCE vulnerability where crafted HTTP requests trigger the installation of a malicious MCP server, resulting in arbitrary code execution. The service binds to 0.0.0.0 by default rather than 127.0.0.1, enabling remote attackers to exploit this vulnerability over the network.

MitigationUpgrade to version 1.4.3 or later to apply the patch. Additionally, configure the service to bind to 127.0.0.1 instead of 0.0.0.0 if remote access is not required, reducing the attack surface.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
InspectorApplication
Affected:< 1.4.3

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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. Check MCPJam Inspector version
    Run 'npm list mcpjam-inspector' or check package.json for the installed mcpjam-inspector package version
    Affected if version is 1.4.2 or earlier (less than 1.4.3)
  2. Check service binding configuration
    Inspect the configuration file or startup script for the MCPJam Inspector service. Look for the 'bind' or 'host' parameter in the configuration
    Affected if the service is bound to 0.0.0.0 instead of 127.0.0.1
  3. Verify network exposure
    Run 'netstat -an | grep <port>' or 'ss -tlnp | grep <port>' to check which addresses the MCPJam Inspector HTTP service is listening on
    Affected if the service is listening on 0.0.0.0 or an external IP address rather than only 127.0.0.1
  4. Check firewall rules
    Review host firewall rules (iptables, ufw, or Windows Firewall) to determine if inbound connections to the MCPJam Inspector port are permitted from non-localhost sources
    Affected if inbound connections from remote hosts are allowed to the MCPJam Inspector port

You are affected if the installed version is 1.4.2 or earlier AND the service is bound to 0.0.0.0 (or accessible remotely), allowing remote attackers to send malicious HTTP requests.

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
Upgrade available Upgrade to 1.4.3 or later
Fixed in 1.4.3
Vendor patch github.com →
Interim mitigation

Upgrade to version 1.4.3 or later to apply the patch. Additionally, configure the service to bind to 127.0.0.1 instead of 0.0.0.0 if remote access is not required, reducing the attack surface.

Recommended fix High confidence

1.4.3

  1. Check current installed version of Inspector (e.g., npm list @mcpjam/inspector or check package.json)
  2. Upgrade Inspector to version 1.4.3 or later using your package manager (e.g., npm install @mcpjam/[email protected] or npm install @mcpjam/inspector@latest)
  3. Verify the upgrade was successful by checking the installed version
  4. Restart the Inspector service to apply the changes

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

Fix this in Inspector Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.

Scan for this in your stack

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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-2026-23744 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data