---
title: "CVE-2026-103091: Google OSS Agent Mesh - Broken Access Control"
description: "Google OSS Agent Mesh (SAM) 0.1.0-alpha.1 through 0.1.0-alpha.8 contains missing authorization and insecure default initialization in MCP proxy and OIDC registration flow, letting remote attackers self-enroll and execute arbitrary actions across MCP backend nodes, exploit requires valid OIDC token."
url: https://panop.io/threat-heartbeat/CVE-2026-103091/
---

# CVE-2026-103091 Google OSS Agent Mesh - Broken Access Control

Google OSS Agent Mesh (SAM) 0.1.0-alpha.1 through 0.1.0-alpha.8 contains missing authorization and insecure default initialization in MCP proxy and OIDC registration flow, letting remote attackers self-enroll and execute arbitrary actions across MCP backend nodes, exploit requires valid OIDC token.

CVSS base score 9.3 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.41% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-103091)

## Details

Type

Broken Access Control

Impact

Remote Code Execution, Data Tampering, Information Disclosure

CVSS vector

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Published

19 October 2026

Updated

20 October 2026

Weakness

[CWE-200](https://cwe.mitre.org/data/definitions/200.html)

## Vendor fix

Upgrade to version 0.1.0-alpha.9 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-103091](https://nvd.nist.gov/vuln/detail/CVE-2026-103091)
- [https://github.com/google/sam/releases/tag/v0.1.0-alpha.9](https://github.com/google/sam/releases/tag/v0.1.0-alpha.9)
- [https://github.com/google/sam/security/advisories/GHSA-cgmg-9xf6-rrgw](https://github.com/google/sam/security/advisories/GHSA-cgmg-9xf6-rrgw)
- [https://github.com/google/agentmesh/security/advisories/GHSA-cgmg-9xf6-rrgw](https://github.com/google/agentmesh/security/advisories/GHSA-cgmg-9xf6-rrgw)

[← All CVEs](https://panop.io/threat-heartbeat/)

## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

[Book a demo](https://panop.io/demo)