Pi-hole has a Stored HTML attribute injection

{
  "id": "add54d9d4144daba2d0fdc2a3def7b7e8dccc045062bffc0fc8fe6b584483ee2",
  "url": "https://osv.dev/vulnerability/CVE-2026-33406",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Pi-hole has a Stored HTML attribute injection",
    "summary": "Pi-hole Admin Interface is a web interface for managing Pi-hole, a network-level ad and internet tracker blocking application. From 6.0 to before 6.5, configuration values from the /api/config endpoint are placed directly into HTML value=\"\" attributes without escaping in settings-advanced.js, enabling HTML attribute injection. A double quote in any config value breaks out of the attribute context. JavaScript execution is blocked by the server's CSP (script-src 'self'), but injected attributes can alter element styling for UI redressing. The primary attack vector is importing a malicious teleporter backup, which bypasses per-field server-side validation. This vulnerability is fixed in 6.5.",
    "evidence": "osv:CVE-2026-33406",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-33406",
      "aliases": [
        "CVE-2026-33406",
        "GHSA-9rfm-c5g6-538p"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/pi-hole/web",
              "type": "GIT",
              "events": [
                {
                  "introduced": "a66d859aecb427faad6adfce144fd97fbeb26a13"
                },
                {
                  "fixed": "7a17e01c28eeb7af2c43384eccf5d859e3061371"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "6.0"
                      },
                      {
                        "fixed": "6.5"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:pi-hole:web_interface:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "6.0"
                      },
                      {
                        "last_affected": "6.4.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v6.4.1",
            "v6.4",
            "v6.3",
            "v6.2.1",
            "v6.1",
            "v6.0.2",
            "v6.0.1",
            "v6.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33406.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:43.002519275Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33406.json",
        "https://github.com/pi-hole/web/security/advisories/GHSA-9rfm-c5g6-538p",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-33406"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33406.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-33406",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 510860,
  "published_at": "2026-04-06T14:50:35.67+00:00"
}