---
id: CVE-2026-102503
title: Missing Authentication on /libp2p-http Ingress in Google OSS Agent Mesh (SAM)
summary: >-
  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.…
severity: critical
cvss: 9.3
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-306
  - CWE-862
vendor: Google
product: github.com/google/sam
affected:
  - github.com/google/sam >= 0.1.0-alpha.1 < 0.1.0-alpha.3
published: '2026-10-19'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T02:20:35.753Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-102503'
references:
  - url: 'https://github.com/google/sam/security/advisories/GHSA-r6hp-67wp-c7jx'
  - url: >-
      https://github.com/google/sam/commit/433bc99d2a2c10071167bf22acc2c930a12e64e1
  - url: 'https://github.com/google/sam/releases/tag/v0.1.0-alpha.3'
tags:
  - cve.org
ingestedAt: '2026-10-19T02:58:59.958Z'
---

## Overview

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.

## Affected

- `github.com/google/sam >= 0.1.0-alpha.1 < 0.1.0-alpha.3`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.