CVE-2025-66414
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 4.0
- 7.6
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 - CVSS 3.1
- 8.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 43% of CVEs (scores of 2026-10-25)
- CWE
- CWE-1188
- Published
- Modified
- Record from
- the NVD, synced
Affected
- lfprojects:mcp_typescript_sdk
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-w48q-cv73-mx4w | npm | @modelcontextprotocol/sdk | <1.24.0 | 1.24.0 |