{"id":"CVE-2026-23744","aliases":["GHSA-232v-j27c-5pp6"],"url":"https://o3.security/vulnerability/CVE-2026-23744","summary":"REC in MCPJam inspector due to HTTP Endpoint exposes","details":"### Summary\nMCPJam inspector is the local-first development platform for MCP servers. The Latest version 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.\n\nThis vulnerability is similar to CVE-2025-49596, but more severe. While CVE-2025-49596 requires tricking a user into clicking a malicious link, this vulnerability is exploitable with no user interaction. 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.\n\n\n\n### Details\nMCPJam inspector binds to `0.0.0.0` making its HTTP APIs remotely reachable.\n``` TypeScript\nconst server = serve({\n  fetch: app.fetch,\n  port: SERVER_PORT,\n  hostname: \"0.0.0.0\",\n});\n```\n\nThe `/api/mcp/connect` API, which is intended for connecting to MCP servers, becomes an open entry point for unauthorized requests. When an HTTP request reaches the `/connect` route, the system extracts the `command` and `args` fields without performing any security checks, leading to the execution of arbitrary command.\n\n### PoC\n(1) Start up the MCPJam inspector as Github README\n`npx @mcpjam/inspector@latest`\n\n(2) RCE by posting a HTTP request\nA remote code execution (RCE) attack can be triggered by sending a simple HTTP request to the target host running MCPJam inspector (e.g., http://10.97.58.83:6274 in the test environment).\n`curl http://10.97.58.83:6274/api/mcp/connect --header \"Content-Type: application/json\" --data \"{\\\"serverConfig\\\":{\\\"command\\\":\\\"cmd.exe\\\",\\\"args\\\":[\\\"/c\\\", \\\"calc\\\"],\\\"env\\\":{}},\\\"serverId\\\":\\\"mytest\\\"}\"`\n\n\n<img width=\"1669\" height=\"1397\" alt=\"image\" src=\"https://github.com/user-attachments/assets/cb6505f1-3cdd-4c64-8f39-a01619a63411\" />\n\n\n### Impact\nRemote Code Execution (RCE)","published":"2026-01-16T20:10:37.458Z","modified":"2026-08-12T03:51:37.280495949Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.64842,"percentile":0.99207,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":8,"affectedPackages":[{"ecosystem":"npm","name":"@mcpjam/inspector","fixedVersion":"1.4.3"}],"fix":{"url":"https://github.com/MCPJam/inspector/commit/e6b9cf9d9e6c9cbec31493b1bdca3a1255fe3e7a","label":"MCPJam/inspector@e6b9cf9"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23744.json"},{"type":"ADVISORY","url":"https://github.com/MCPJam/inspector/security/advisories/GHSA-232v-j27c-5pp6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23744"},{"type":"FIX","url":"https://github.com/MCPJam/inspector/commit/e6b9cf9d9e6c9cbec31493b1bdca3a1255fe3e7a"},{"type":"PACKAGE","url":"https://github.com/MCPJam/inspector"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:37.280495949Z"}}