CVE-2026-23744
Published: 16 January 2026
Summary
CVE-2026-23744 is a critical-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Mcpjam Inspector. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 1.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.
The strongest mitigations our analysis identified are NIST 800-53 AC-14 (Permitted Actions Without Identification or Authentication) and SC-14 (Public Access Protections).
Deeper analysis
CVE-2026-23744 is a remote code execution (RCE) vulnerability affecting MCPJam inspector, a local-first development platform for MCP servers, in versions 1.4.2 and earlier. The flaw, linked to CWE-306 (Missing Authentication for Critical Function), arises when a crafted HTTP request triggers the unintended installation of an MCP server, enabling RCE. By default, MCPJam inspector binds to 0.0.0.0 rather than 127.0.0.1, exposing the service to remote networks. The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity.
Any unauthenticated remote attacker can exploit this vulnerability by sending a simple crafted HTTP request to the exposed MCPJam inspector instance. Successful exploitation grants arbitrary code execution on the target system with the privileges of the inspector process, potentially leading to full system compromise, data theft, or further lateral movement.
The patch is available in version 1.4.3 of MCPJam inspector. Official advisories and the fixing commit are detailed in the GitHub security advisory (GHSA-232v-j27c-5pp6) and the patch commit (e6b9cf9d9e6c9cbec31493b1bdca3a1255fe3e7a), recommending immediate upgrade to mitigate the issue.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-2859
Vulnerability details
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,…
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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.
- CWE(s)
AI Security AnalysisAI
- AI Category
- AI Agent Protocols and Integrations
- Risk Domain
- Protocol-Specific Risks
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: mcp
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability enables unauthenticated remote code execution via crafted HTTP requests to the exposed MCPJam inspector service (binding to 0.0.0.0), directly facilitating T1190: Exploit Public-Facing Application.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Flaw remediation requires timely patching to version 1.4.3, which directly eliminates the RCE vulnerability from crafted HTTP requests.
Limits permitted actions without identification or authentication, directly addressing the missing authentication (CWE-306) for the critical MCP server installation function.
Enforces access controls on publicly accessible services like the default 0.0.0.0-bound MCPJam inspector HTTP endpoint to block unauthorized remote exploitation.