HeyForm has unauthenticated /api/upload endpoint that accepts arbitrary files with no auth/session/form context

{
  "id": "d6e47df3ecb296d6a6966857809a7467034bedc6e38cec352d59e99317ed74e3",
  "url": "https://osv.dev/vulnerability/CVE-2026-63429",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "HeyForm has unauthenticated /api/upload endpoint that accepts arbitrary files with no auth/session/form context",
    "summary": "HeyForm is an open-source form builder. Prior to version 3.0.0-rc.9, `POST /api/upload` has no authentication guard, no global guard, no form-context validation, no `openToken` requirement, and no session cookie check. Any anonymous internet user can upload files (PDF, DOC/DOCX, XLS/XLSX, CSV, TXT, MP4, images, etc., up to 10 MB) and receive a permanent public URL on the HeyForm domain. The endpoint is used by both authenticated form creators and unauthenticated form submitters; because no form-context binding exists, every request to it is anonymously accepted. Version 3.0.0-rc.9 contains a patch for the issue.",
    "evidence": "osv:CVE-2026-63429",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-63429",
      "aliases": [
        "CVE-2026-63429",
        "GHSA-432x-54v2-p7p7"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/heyform/heyform",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "84d8c9993ae1c89b9a9e4793dac4331a26b12ba3"
                },
                {
                  "fixed": "092e255e9e02565de1b3c057f3dad849160952d2"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.0.0-rc.9"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "092e255e9e02565de1b3c057f3dad849160952d2"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.0.0-rc.8",
            "v3.0.0-rc.7",
            "v3.0.0-rc.6",
            "v3.0.0-rc.5",
            "v3.0.0-rc.4",
            "v3.0.0-rc.3",
            "v3.0.0-rc.2",
            "v3.0.0-rc.1",
            "v3.0.0-alpha.3",
            "v3.0.0-alpha-2",
            "v0.1.0",
            "v0.0.17",
            "v0.0.16",
            "v0.0.15",
            "v0.0.13",
            "v0.0.12",
            "v0.0.11",
            "v0.0.10",
            "v0.0.9",
            "v0.0.8",
            "v0.0.7",
            "v0.0.6",
            "v0.0.5",
            "v0.0.4",
            "v0.0.3",
            "v0.0.2",
            "v0.0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63429.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.175927026Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63429.json",
        "https://github.com/heyform/heyform/security/advisories/GHSA-432x-54v2-p7p7",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-63429",
        "https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-306",
          "CWE-434"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63429.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-63429",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517503,
  "published_at": "2026-07-20T15:54:22.075+00:00"
}