Google SAM up to 0.1.0-alpha.2 Libp2p-http ingress cmd/sam-node/node.go StartIngressServer missing authentication

Summaryinfo

A vulnerability classified as critical was found in Google SAM up to 0.1.0-alpha.2. Impacted is the function StartIngressServer of the file cmd/sam-node/node.go of the component Libp2p-http ingress. Such manipulation leads to missing authentication. This vulnerability is referenced as CVE-2026-102503. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Google SAM up to 0.1.0-alpha.2 and classified as critical. Affected by this issue is the function StartIngressServer of the file cmd/sam-node/node.go of the component Libp2p-http ingress. The manipulation with an unknown input leads to a missing authentication vulnerability. Using CWE to declare the problem leads to CWE-306. The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-102503 since 09/29/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/19/2026).

Upgrading to version 0.1.0-alpha.3 eliminates this vulnerability.

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Productinfo

Vendor

• Google

Name

• SAM

Version

• 0.1.0-alpha.0
• 0.1.0-alpha.1
• 0.1.0-alpha.2

License

• free

Website

• Vendor: https://www.google.com/
• Product: https://github.com/google/sam/

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