CVE-2026-103091

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Source
https://cve.org/CVERecord?id=CVE-2026-103091
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-103091.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-103091
Aliases
  • GHSA-cgmg-9xf6-rrgw
Published
2026-10-19T02:24:35Z
Modified
2026-10-21T02:54:30Z
Severity
  • 9.3 (Critical) CVSS_V4 - 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 CVSS Calculator
Summary
Insecure Default Policy and Unrestricted OIDC Enrollment in Google OSS Agent Mesh (SAM)
Details

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.

Database specific 
{
    "cna_assigner":  "Google",
    "cwe_ids":  [
        "CWE-1188",
        "CWE-200",
        "CWE-306",
        "CWE-862",
        "CWE-863"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103091.json"
}
References

Affected packages

Git / github.com/google/agentmesh

Affected ranges

Type
GIT
Repo
https://github.com/google/agentmesh
Events
Introduced
ffc3e6072383ea6e9cf3fbadc7cf473db448b364
Fixed
bcf9bc22e5f4bb00eb504c1ab5f55815e0e91f23
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "0.1.0-alpha.1"
                },
                {
                    "fixed":  "0.1.0-alpha.9"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StandardRange"
        },
        {
            "original_tag":  "v0.1.0-alpha.9",
            "range":  [
                {
                    "fixed":  "bcf9bc22e5f4bb00eb504c1ab5f55815e0e91f23"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-103091.json"