{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "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"
              }
            ]
          },
          "events": [
            {
              "introduced": "ffc3e6072383ea6e9cf3fbadc7cf473db448b364"
            },
            {
              "fixed": "bcf9bc22e5f4bb00eb504c1ab5f55815e0e91f23"
            }
          ],
          "repo": "https://github.com/google/agentmesh",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-cgmg-9xf6-rrgw"
  ],
  "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"
  },
  "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.",
  "id": "CVE-2026-103091",
  "modified": "2026-10-21T02:30:29.948112864Z",
  "published": "2026-10-19T02:24:35.225Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103091.json"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/google/agentmesh/security/advisories/GHSA-cgmg-9xf6-rrgw"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/google/sam/releases/tag/v0.1.0-alpha.9"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/google/sam/security/advisories/GHSA-cgmg-9xf6-rrgw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103091"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Insecure Default Policy and Unrestricted OIDC Enrollment in Google OSS Agent Mesh (SAM)"
}