Missing Authentication and Authorization in Google OSS Agent Mesh
CVE-2026-102503

9.3CRITICAL

Key Information:

Vendor

Google
Status
Sam
Vendor
CVE Published:
19 October 2026

What is CVE-2026-102503?

A vulnerability exists in the OSS Agent Mesh that allows unauthenticated remote libp2p peers to bypass critical Biscuit capability policy enforcement. Specifically, the ingress server at /libp2p-http can enable unrestricted access to registered backend services, including MCP servers and inference endpoints, without validating a Biscuit token or ensuring mesh enrollment. Users are strongly advised to upgrade to version 0.1.0-alpha.3 or later to mitigate this security risk.

Affected Version(s)

SAM 0.1.0-alpha.1 < 0.1.0-alpha.3

References

https://github.com/google/sam/security/advisories/GHSA-r6...
vendor-advisory
https://github.com/google/sam/commit/433bc99d2a2c10071167...
patch
https://github.com/google/sam/releases/tag/v0.1.0-alpha.3
release-notes

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Yanchon918s
.