{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.1.0"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "b211fdaed3b6829e126edaeb6b43503849c062a0"
            }
          ],
          "repo": "git://github.com/maximhq/bifrost",
          "type": "GIT"
        },
        {
          "database_specific": {
            "source": "REFERENCES"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "12e170352bd25eab1ae9ba16611f1797d1fd8fdc"
            }
          ],
          "repo": "https://github.com/maximhq/bifrost",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "JFROG",
    "cwe_ids": [
      "CWE-284",
      "CWE-306"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90898.json"
  },
  "details": "Bifrost registers MCP clients through its management API. A stdio client is a command plus args. Bifrost starts that program in the gateway the moment the client is added. No MCP handshake required.\n\n\n\nThe default is governance.auth_config.is_enabled=false. Auth off means every caller is a local admin. One unauthenticated POST /api/mcp/client is enough to run a program as the Bifrost process user (appuser on the official image).\n\n\n\n transports/v2.1.0 refuses an unauthenticated stdio registration with 403. transports/v2.0.0 still allows it.",
  "id": "CVE-2026-90898",
  "modified": "2026-09-16T03:30:19.397934828Z",
  "published": "2026-09-14T10:18:53.454Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90898.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/maximhq/bifrost/releases/tag/transports/v2.1.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90898"
    },
    {
      "type": "FIX",
      "url": "https://github.com/maximhq/bifrost/commit/12e170352bd25eab1ae9ba16611f1797d1fd8fdc"
    },
    {
      "type": "FIX",
      "url": "https://github.com/maximhq/bifrost/pull/6757"
    },
    {
      "type": "PACKAGE",
      "url": "git://github.com/maximhq/bifrost"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/maximhq/bifrost"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Bifrost unauthenticated remote code execution via MCP stdio client registration"
}