{"cve":"CVE-2025-66414","nvd":{"published":"2025-12-02T19:15:52.347","modified":"2026-10-18T18:10:00.100","status":"Analyzed","description":"MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. Prior to 1.24.0, The Model Context Protocol (MCP) TypeScript SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an HTTP-based MCP server is run on localhost without authentication with StreamableHTTPServerTransport or SSEServerTransport and has not enabled enableDnsRebindingProtection, a malicious website could exploit DNS rebinding to bypass same-origin policy restrictions and send requests to the local MCP server. This could allow an attacker to invoke tools or access resources exposed by the MCP server on behalf of the user in those limited circumstances. Note that running HTTP-based MCP servers locally without authentication is not recommended per MCP security best practices. This issue does not affect servers using stdio transport. This vulnerability is fixed in 1.24.0.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","score":7.6},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","score":8.1},"cwes":["CWE-1188"],"references":["https://github.com/modelcontextprotocol/typescript-sdk/commit/09623e2aa5044f9e9da62c73d820a8250b9d97ed","https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-w48q-cv73-mx4w"],"products":["lfprojects:mcp_typescript_sdk"],"source":"nvd","synced_at":"2026-10-19T22:16:02.354564667+00:00"},"epss":{"cve":"CVE-2025-66414","score":0.00511,"percentile":0.43329,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-w48q-cv73-mx4w","url":"https://osv.dev/vulnerability/GHSA-w48q-cv73-mx4w","summary":"Model Context Protocol (MCP) TypeScript SDK does not enable DNS rebinding protection by default","modified":"2026-09-10T03:49:54.319259730Z","packages":[{"ecosystem":"npm","name":"@modelcontextprotocol/sdk","purl":"pkg:npm/%40modelcontextprotocol/sdk","ranges":["<1.24.0"],"fixed":["1.24.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}