Missing Authorization (CWE-862) and Initialization of a Resource with an Insecure Default (CWE-1188) in the MCP proxy (HandleStreamPassThrough in mcp_service.go) and OIDC registration flow (GET /info and POST /register in internal/controlplane/server.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 allow a remote attacker to self-enroll into the mesh and invoke arbitrary tools across all connected MCP backend nodes. Because GET /info publicly discloses OIDC configuration, POST /register auto-enrolls any valid OIDC token holder without claim filtering or ban checks, and the default policy binds sam:system:authenticated to wildcard services and targets, an attacker can obtain a mesh credential with full read, write, and execution access on backend services. Users should upgrade to version 0.1.0-alpha.9 or later, which enforces a fail-closed default policy, explicit policy-binding requirements on enrollment, and ban checks.
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Mon, 19 Oct 2026 02:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Missing Authorization (CWE-862) and Initialization of a Resource with an Insecure Default (CWE-1188) in the MCP proxy (HandleStreamPassThrough in mcp_service.go) and OIDC registration flow (GET /info and POST /register in internal/controlplane/server.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 allow a remote attacker to self-enroll into the mesh and invoke arbitrary tools across all connected MCP backend nodes. Because GET /info publicly discloses OIDC configuration, POST /register auto-enrolls any valid OIDC token holder without claim filtering or ban checks, and the default policy binds sam:system:authenticated to wildcard services and targets, an attacker can obtain a mesh credential with full read, write, and execution access on backend services. Users should upgrade to version 0.1.0-alpha.9 or later, which enforces a fail-closed default policy, explicit policy-binding requirements on enrollment, and ban checks. | |
| Title | Insecure Default Policy and Unrestricted OIDC Enrollment in Google OSS Agent Mesh (SAM) | |
| Weaknesses | CWE-1188 CWE-200 CWE-306 CWE-862 CWE-863 |
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cvssV4_0
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Status: PUBLISHED
Assigner: Google
Published:
Updated: 2026-10-19T02:24:35.225Z
Reserved: 2026-09-30T01:36:24.048Z
Link: CVE-2026-103091
No data.
Status : Received
Published: 2026-10-19T03:16:58.377
Modified: 2026-10-19T03:16:58.377
Link: CVE-2026-103091
No data.
OpenCVE Enrichment
Updated: 2026-10-19T03:30:06Z