{"id":"CVE-2026-39885","aliases":["GHSA-v6ph-xcq9-qxxj"],"url":"https://o3.security/vulnerability/CVE-2026-39885","summary":"FrontMCP Affected by SSRF via $ref Dereferencing in Untrusted OpenAPI Specifications","details":"FrontMCP is a TypeScript-first framework for the Model Context Protocol (MCP). Prior to 2.3.0, the mcp-from-openapi library uses @apidevtools/json-schema-ref-parser to dereference $ref pointers in OpenAPI specifications without configuring any URL restrictions or custom resolvers. A malicious OpenAPI specification containing $ref values pointing to internal network addresses, cloud metadata endpoints, or local files will cause the library to fetch those resources during the initialize() call. This enables Server-Side Request Forgery (SSRF) and local file read attacks when processing untrusted OpenAPI specifications. This vulnerability is fixed in 2.3.0.","published":"2026-04-08T20:34:20.538Z","modified":"2026-08-05T03:47:30.598746942Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"mcp-from-openapi","fixedVersion":"2.3.0"},{"ecosystem":"npm","name":"@frontmcp/sdk","fixedVersion":"1.0.4"},{"ecosystem":"npm","name":"@frontmcp/adapters","fixedVersion":"1.0.4"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/agentfront/frontmcp/releases/tag/v1.0.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39885.json"},{"type":"ADVISORY","url":"https://github.com/agentfront/frontmcp/security/advisories/GHSA-v6ph-xcq9-qxxj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39885"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-05T03:47:30.598746942Z"}}