npm/@modelcontextprotocol/server-legacy CVE-2026-111771: medium 6.8

MCP TypeScript SDK: Server bearer authentication accepted tokens issued for another service

Action: Upgrade @modelcontextprotocol/server-legacy to 2.3.1 or later.

npm i @modelcontextprotocol/server-legacy@2.3.1

Affected

Fixed versions

Sources

• osv: GHSA-rvq5-wwqv-78pq#npm/@modelcontextprotocol/server-legacy
• https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-rvq5-wwqv-78pq
• https://github.com/modelcontextprotocol/typescript-sdk/commit/40f8f4e229d963cd7fd2890bda2aeebe7005299a
• https://github.com/modelcontextprotocol/typescript-sdk/commit/5a0724d14cf34a27a3b070224d2996cdd611df9f
• https://github.com/modelcontextprotocol/typescript-sdk/commit/5a1867390b91b8836f49af76c45427279f513325
• https://github.com/modelcontextprotocol/typescript-sdk

CVE-2026-111771 · published 2026-10-20T19:43:36Z · modified 2026-10-20T20:00:04.595309934Z · JSON