{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-59973",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-07-07T19:41:00.004Z",
        "datePublished": "2026-09-15T15:13:40.053Z",
        "dateUpdated": "2026-09-15T15:13:40.053Z"
    },
    "containers": {
        "cna": {
            "title": "mcp-from-openapi: Bypass of OpenAPI external $ref SSRF fix in latest FrontMCP and mcp-from-openapi",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-918",
                            "lang": "en",
                            "description": "CWE-918: Server-Side Request Forgery (SSRF)",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 8.5,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "LOW",
                        "privilegesRequired": "LOW",
                        "scope": "CHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/agentfront/frontmcp/security/advisories/GHSA-65h7-9wrw-629c",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/agentfront/frontmcp/security/advisories/GHSA-65h7-9wrw-629c"
                },
                {
                    "name": "https://github.com/agentfront/frontmcp/pull/496",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/agentfront/frontmcp/pull/496"
                },
                {
                    "name": "https://github.com/agentfront/mcp-from-openapi/pull/7",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/agentfront/mcp-from-openapi/pull/7"
                },
                {
                    "name": "https://github.com/agentfront/frontmcp/commit/96a78eaa5c6c4bc51cced557d83d1a03344cb03d",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/agentfront/frontmcp/commit/96a78eaa5c6c4bc51cced557d83d1a03344cb03d"
                },
                {
                    "name": "https://github.com/agentfront/mcp-from-openapi/commit/be3409cce6e97642696d4ee5a4e4e2712490b277",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/agentfront/mcp-from-openapi/commit/be3409cce6e97642696d4ee5a4e4e2712490b277"
                },
                {
                    "name": "https://github.com/agentfront/frontmcp/releases/tag/v1.5.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/agentfront/frontmcp/releases/tag/v1.5.0"
                },
                {
                    "name": "https://github.com/agentfront/mcp-from-openapi/releases/tag/v2.5.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/agentfront/mcp-from-openapi/releases/tag/v2.5.0"
                }
            ],
            "affected": [
                {
                    "vendor": "agentfront",
                    "product": "frontmcp",
                    "versions": [
                        {
                            "version": "< 1.5.0",
                            "status": "affected"
                        }
                    ]
                },
                {
                    "vendor": "agentfront",
                    "product": "mcp-from-openapi",
                    "versions": [
                        {
                            "version": "< 2.5.0",
                            "status": "affected"
                        }
                    ]
                },
                {
                    "vendor": "@frontmcp",
                    "product": "adapters",
                    "versions": [
                        {
                            "version": "< 1.5.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-09-15T15:13:40.053Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "FrontMCP is a TypeScript-first framework for the Model Context Protocol (MCP). From mcp-from-openapi 2.3.0 until 2.5.0 and from frontmcp and @frontmcp/adapters 1.2.1 until 1.5.0, libs/adapters/src/openapi/openapi.adapter.ts loadOpenAPISpec() forwards untrusted OpenAPI url and spec inputs and loadOptions.refResolution to OpenAPIToolGenerator.fromURL() and OpenAPIToolGenerator.fromJSON(). The external $ref guard checks parsed hostname strings without resolving addresses, pinning validated addresses, revalidating redirect targets, or normalizing IPv4-mapped IPv6. An authenticated user who can import or configure an OpenAPI specification in a hosted or multi-user deployment can use DNS-to-loopback resolution, redirect-to-loopback behavior, or IPv4-mapped IPv6 loopback forms to cause backend-origin requests to internal services. This can expose internal administrative APIs, metadata-like services, and other private network endpoints. The practical impact is lower when only a trusted local administrator can configure OpenAPI specs, and disabling external reference protocols prevents the external $ref request. This issue is fixed in mcp-from-openapi 2.5.0 and frontmcp and @frontmcp/adapters 1.5.0."
                }
            ],
            "source": {
                "advisory": "GHSA-65h7-9wrw-629c",
                "discovery": "UNKNOWN"
            }
        }
    }
}