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.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63429.json",
"cwe_ids": [
"CWE-306",
"CWE-434"
],
"cna_assigner": "GitHub_M"
}