{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "0.29.1"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "26912af453d2040787983dbc9ab93a9019ec0468"
            },
            {
              "fixed": "83e9eaec177c85c791a337b8c99d2e43c06904a1"
            }
          ],
          "repo": "https://github.com/stacklok/toolhive",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-pph6-vfjv-vpjw"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54450.json"
  },
  "details": "ToolHive is a utility designed to simplify the deployment and management of Model Context Protocol (MCP) servers. Prior to 0.29.1, networking.IsPrivateIP in pkg/networking/utilities.go omits the IPv6 NAT64 prefixes 64:ff9b::/96 and 64:ff9b:1::/48, so NAT64 addresses embedding private, loopback, or link-local IPv4 targets are classified as public and allowed. The most direct attacker-controlled path begins when an external OAuth client supplies a client_id URL that CIMDStorageDecorator.GetClient routes through FetchClientMetadataDocument in pkg/oauthproto/cimd/fetch.go; protectedDialerControl in pkg/networking/http_client.go and validateHost in pkg/skills/gitresolver/reference.go share the defective classification but use operator-controlled or user-controlled destinations. On a ToolHive host behind a NAT64/DNS64 gateway, the gateway translates an allowed address such as 64:ff9b:1::a9fe:a9fe to 169.254.169.254, permitting blind probing of internal TCP or TLS reachability. The attacker-controlled CIMD path requires HTTPS, verifies certificates, and does not reflect response bodies, so the established impact is an internal reachability oracle rather than metadata credential exfiltration; the webhook client is not affected because it does not use this IP guard. This issue is fixed in version 0.29.1.",
  "id": "CVE-2026-54450",
  "modified": "2026-09-17T03:30:44.355060107Z",
  "published": "2026-09-15T15:47:39.377Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/stacklok/toolhive/releases/tag/v0.29.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54450.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/stacklok/toolhive/security/advisories/GHSA-pph6-vfjv-vpjw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54450"
    },
    {
      "type": "FIX",
      "url": "https://github.com/stacklok/toolhive/commit/26912af453d2040787983dbc9ab93a9019ec0468"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "ToolHive: SSRF guard misses IPv6 NAT64 ranges (64:ff9b::/96, 64:ff9b:1::/48), allowing metadata/internal access behind a NAT64 gateway"
}