CVE-2026-102503: critical vulnerability in Google SAM
Missing Authentication on /libp2p-http Ingress in Google OSS Agent Mesh (SAM)
Published
48Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 9.3epss 0.4%
exploitation probability
0.4%top 63% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
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.
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
Affected products
Google · SAMpublic PoCs found — 1
cve_referencegithub.com/google/agentmesh/security/advisories/GHSA-r6hp-67wp-c7jxunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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