CVE-2026-102503
CriticalCVSS 9.3Exploitation Probability (EPSS)
Low risk27th percentile - higher than 27% of all known CVEs
Summary
Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.2 contain Missing Authentication for Critical Function (CWE-306) and Missing Authorization (CWE-862) in the /libp2p-http ingress server. An unauthenticated remote libp2p peer can bypass Biscuit capability policy enforcement and invoke arbitrary registered backend services, including command/stdio-backed MCP servers, A2A, and inference endpoints.
Risk Assessment
An unauthenticated attacker can invoke critical backend services, potentially leading to unauthorized data access and command execution.
Recommendation
Upgrade Google OSS Agent Mesh to version 0.1.0-alpha.3 or later.
Other vulnerabilities in Google OSS Agent Mesh (SAM)
See all- CVE-2026-103091Critical
Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 contain Missing Authorization (CWE-862) and Insecure Default Initialization (CWE-1188) in the MCP proxy and OIDC registration flow. Public disclosure of OIDC configuration via GET /info and auto-enrollment of any valid OIDC token holder via POST /register without claim filtering or ban checks allow a remote attacker to self-enroll into the mesh and invoke arbitrary tools across all connected MCP backend nodes.
- CVE-2026-103090High
Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 lack authentication in the enrollment status handler (GET /enroll/status). An unauthenticated remote attacker can retrieve an approved peer's signed Biscuit identity token by supplying a peer_id from the unauthenticated GET /info endpoint, then replay it as a bearer credential to read authorization policies and overwrite router multiaddrs.
Original NVD description (English source)
Missing Authentication for Critical Function (CWE-306) and Missing Authorization (CWE-862) in the /libp2p-http ingress server (StartIngressServer in cmd/sam-node/node.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.2 allow an unauthenticated remote libp2p peer to bypass Biscuit capability policy enforcement and invoke arbitrary registered backend services (including command/stdio-backed MCP servers, A2A, and inference endpoints). While the MCP protocol stream handler enforces WithBiscuitAuth and Authorize checks, the parallel /libp2p-http ingress routes requests directly to backend service handlers without verifying a Biscuit token or mesh enrollment. Users should upgrade to version 0.1.0-alpha.3 or later.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS