KEV Intelligence

Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2026-23744

REC in MCPJam inspector due to HTTP Endpoint exposes

MCPJam / inspector · <= 1.4.2

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Severity
CVSS 9.8 · Critical
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
45.0%
First observed
03 Jul 2026
Last observed
16 Aug 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-23744 is an unauthenticated REC in MCPJam inspector due to HTTP Endpoint exposes. MCPJam inspector is the local-first development platform for MCP servers. Versions 1.4.2 and earlier are vulnerable to remote...

Is it exploited?

Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.

Who is affected?

MCPJam / inspector <= 1.4.2.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

MCPJam inspector is the local-first development platform for MCP servers

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.

Vendor Product Affected Status
MCPJam inspector <= 1.4.2 Affected
Published
16 Jan 2026
Exploitation Reported
03 Apr 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

nuclei_scanner

CVE References

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

The Shadowserver

Recorded 03 Apr 2026

Independent exploitation attestation added to the KEV Intelligence record.

Active exploitation observed

KEV Intelligence sensor

First observed 03 Jul 2026

First-party sensor telemetry confirms matching exploitation attempts.

Proof of concept available

GitHub

Recorded 29 Mar 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
The Shadowserver First 2026-04-03 00:00 UTC
KEV Intelligence 2026-07-30 16:09 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.

8

Attempts observed

4

Unique attacker IPs

4

Attacker countries

IR · JP · NL · US

6

Sensors observed

Exploitation attempts over the last 49 days

Daily events observed by KEV Intelligence sensors

Updated 19 Aug 2026

0
9
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
2
2
0
0
0
2 Jul 12 Jul 22 Jul 1 Aug 19 Aug

First observed 03 Jul 2026 · Last observed 16 Aug 2026

Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
1
User-Agents
5

Raw values available in Pro and Enterprise.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

Learn about Pro API access

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-23744.yaml 01 Jun 2026

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

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

EPSS

45.0%

Weaknesses

Missing Authentication for Critical Function CWE-306

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

sonnelon/CVE-2026-23744-PoC

github · Created 2026-08-10 15:57:48 UTC · 0 stars · AI assessment 90%

Mluex0/CVE-2026-23744-PoC

github · Created 2026-08-10 09:07:16 UTC · 0 stars · AI assessment 90%

CVE-2026-23744 is an unauthenticated command injection in MCPJam Inspector ≤1.4.2 via /api/mcp/connect. This POC exploits it by sending a crafted JSON payload to execute arbitrary commands, granting a reverse shell with PTY.

MCPJam Inspector - Remote Code Execution

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. Observed by KEV Intelligence sensors

    Evidence-backed exploitation signal

  2. Indicators of compromise added (11)

    Indicators of compromise recorded

  3. Public PoC available

    Public proof-of-concept code published

  4. Nuclei template available

    Scanner coverage available

  5. Added to KEV Intelligence KEV Feed

    High-confidence, third-party attested exploitation

  6. CVE published

    Vulnerability disclosed publicly

  7. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-23744

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-23744",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.45026,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 8, "sensors": 6 }
}

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