Missing Authentication on /libp2p-http Ingress in Google OSS Agent Mesh (SAM)
Classification: Critical, Solution: Official Fix, Exploit Maturity: Proof-of-Concept, CVSSv4.0: 9.3, CVEs: CVE-2026-102503, Summary: A SAM node exposes its registered backend services (MCP / A2A / inference, including command/stdio-backed MCP servers) over two libp2p paths. The MCP-protocol path is wrapped in WithBiscuitAuth -> Authorize, which enforces the node's biscuit policy (allowed_tools / allowed_targets). The parallel /libp2p-http ingress reaches the same backend service handlers with…
EPSS 0.00 CVSS 9.3 CVE-2026-102503 Google FI