CVE-2026-81094
CriticalCVSS 9.1Summary
The mcp-router CLI served its MCP aggregator on every interface and enforced authentication only when the operator asked for it. A default invocation exposed the aggregator and every MCP server it fronted to anyone able to reach the port. Release 0.6.3 defaults the host to loopback and refuses to start without a token when the host is not loopback.
Risk Assessment
Risk of unauthorized access to the MCP aggregator and all MCP servers, potentially leading to data exposure or unauthorized operations.
Recommendation
Upgrade mcp-router to version 0.6.3 or later and always provide an authentication token when the server is reachable externally.
Original NVD description (English source)
The mcp-router CLI served its MCP aggregator on every interface and enforced authentication only when the operator asked for it. The serve command in apps/cli/src/commands/serve.ts defaulted its host to the all-interfaces address on a fixed port, and required a token only when the corresponding flag was supplied, so a default invocation exposed the aggregator, and every MCP server it fronted, to anyone able to reach the port. Release 0.6.3 defaults the host to the loopback address and refuses to start without a token whenever the host it is given is not a loopback address; no earlier release carries either check.