Paper/Archive/CVE-2026-102503

CVE-2026-102503

Google SAM — Missing Authentication on /libp2p-http Ingress in Google OSS Agent Mesh (SAM)

CVSS 9.3 (CNA)9.3 / 10 × 3027.9 Not in CISA KEV+300.0 EPSS percentile 37.2.372 × 207.4 Exploit: SSVC poc+1010.0 SSVC exploitation: poc+100.0

Description · from the CVE record

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

ProductAffectedFixed inSource

SAM0.1.0-alpha.1 – < 0.1.0-alpha.30.1.0-alpha.3CNA

Scores by source

Google (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CISA ADPSSVCExploitation: poc · Automatable: yes · Technical impact: total

References

advisorygithub.com/google/sam/security/advisories/GHSA-r6hp-67wp-c7jx patchgithub.com/google/sam/commit/433bc99d2a2c10071167bf22acc2c930a12e64e1 refgithub.com/google/sam/releases/tag/v0.1.0-alpha.3 exploitgithub.com/google/agentmesh/security/advisories/GHSA-r6hp-67wp-c7jx