Security advisory

{
  "id": "bbc20e2645c7dd3b876c3e78d50dde63d9fe2c3f9e572d0011a58d76087068fa",
  "url": "https://osv.dev/vulnerability/CVE-2026-50248",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-50248",
    "summary": "In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, when an auth/rpz zone has a configured primary hostname that resolves to BOGUS A/AAAA, it is still considered as a possible XFR endpoint. A malicious actor that can spoof the hostname's A/AAAA record (no valid RRSIG required) becomes the zone's XFR primary and can replaces the entire zone/the resolver's entire response policy.",
    "evidence": "osv:CVE-2026-50248",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-50248",
      "aliases": [
        "CVE-2026-50248"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nlnetlabs/unbound",
              "type": "GIT",
              "events": [
                {
                  "introduced": "50bd12d6953ef1bca9e5f87cd1ebb5e4b7688241"
                },
                {
                  "fixed": "c33ad1b1a21e48bfe4f140e90252a9be1b0c5745"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.7.0"
                      },
                      {
                        "fixed": "1.25.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50248.json"
          }
        }
      ],
      "modified": "2026-10-27T17:27:11.468735774Z",
      "provider": "osv",
      "references": [
        "https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-50248.txt"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2026-50248",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 463030,
  "published_at": "2026-07-22T14:17:20.37+00:00"
}