---
id: "CVE-2026-102503"
kind: "vulnerability"
aliases: ["CVE-2026-102503"]
title: "Missing Authentication for Critical Function (CWE-306) and Missing Authorization (CWE-862) in the /libp2p-http\u2026"
severity: "critical"
cvss: 9.3
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: []
ecosystems: []
tags: ["a2a", "agent-mesh", "ai-tooling", "libp2p", "mcp", "self-hosted"]
not_affected_if: ["version-0.1.0-alpha.3-or-later"]
published_at: "2026-10-19T03:16:58+00:00"
first_seen_at: "2026-10-23T21:57:17+00:00"
updated_at: "2026-10-23T22:28:56+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-102503", "first_seen_at": "2026-10-23T21:57:17+00:00"}]
---

# Missing Authentication for Critical Function (CWE-306) and Missing Authorization (CWE-862) in the /libp2p-http…

Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.2 expose a /libp2p-http ingress that forwards requests to backend services without checking Biscuit tokens or mesh enrollment. An unauthenticated remote libp2p peer can invoke any registered backend, including command-backed MCP servers, A2A and inference endpoints.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

Check the installed SAM version and confirm it is 0.1.0-alpha.1 or 0.1.0-alpha.2.

## Fix

Upgrade to version 0.1.0-alpha.3 or later.

## Timeline

- 2026-10-23T21:57:17+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-102503

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_