CVE-2026-81094

Published: Ago 27, 2026 Last Modified: Ago 27, 2026
ExploitDB:
Other exploit source:
Google Dorks:
CRITICAL 9,3
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A
CRITICAL 9,1
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

Draft
Common Consequences
Security Scopes Affected:
Access Control Other
Potential Impacts:
Gain Privileges Or Assume Identity Varies By Context
Applicable Platforms
Technologies: Cloud Computing, ICS/OT
View CWE Details
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-…