CVE-2026-81094
CRITICAL
9,3
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A
CRITICAL
9,1
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: none
Description
AI Translation Available
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.
306
Missing Authentication for Critical Function
DraftCommon Consequences
Security Scopes Affected:
Access Control
Other
Potential Impacts:
Gain Privileges Or Assume Identity
Varies By Context
Applicable Platforms
Technologies:
Cloud Computing, ICS/OT
https://github.com/mcp-router/mcp-router
https://github.com/mcp-router/mcp-router/blob/v0.6.3/apps/cli/src/commands/serv…
https://github.com/mcp-router/mcp-router/commit/4c4642cfd274097ec8b33ecd3047390…
https://github.com/mcp-router/mcp-router/security/advisories/GHSA-rx55-5c7h-r56r
https://www.vulncheck.com/advisories/mcp-router-cli-before-0.6.3-binds-the-mcp-…