CVE-2026-102503
9.3CriticalPublished 19 Oct 2026 · NVD status: Received · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Impact
- Full C/I/A compromise
- Weakness
- CWE-306, CWE-862
Impact
Unauthenticated remote libp2p peers can execute arbitrary registered backend services, including command-backed MCP servers and inference endpoints. An attacker only needs network access to the peer interface to trigger this without credentials.
Root cause
The /libp2p-http ingress handler routes incoming traffic straight to backend services without performing Biscuit token verification or mesh enrollment checks.
Affected systems
Google OSS Agent Mesh (SAM) 0.1.0-alpha.1 through 0.1.0-alpha.2
CVSS v4.0 · 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
Fix & remediation
Upgrade SAM to version 0.1.0-alpha.3 or later. If upgrading must wait, block or restrict untrusted network access to the libp2p ingress port.
AI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
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.