CVE-2026-63429 Details
Description
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.
A critical vulnerability in HeyForm's file upload feature allows any anonymous user to upload files without authentication or proper validation. The issue exists in versions through 3.0.0-rc.8. The /api/upload endpoint lacks authentication guards, session checks, and form-context validation, enabling unrestricted file uploads of various types, including documents, images, and videos, up to 10 MB. Uploaded files receive a permanent public URL on the HeyForm domain, which can be exploited to distribute malicious content or phishing attacks.
Users are advised to update to HeyForm version 3.0.0-rc.9 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 20, 2026CISA-ADP
Assessed Jul 20, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/heyform/heyform/security/advisories/GHSA-432x-54v2-p7p7 | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2 | [email protected] | Source CodeVendor |
| https://github.com/heyform/heyform/security/advisories/GHSA-432x-54v2-p7p7 | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-306 | Missing Authentication for Critical Function | [email protected] |
| CWE-434 | Unrestricted Upload of File with Dangerous Type | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| HeyForm | <= 3.0.0-rc.8 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 20, 2026 | CVE Modified | CISA-ADP |
| Jul 20, 2026 | New CVE Received | [email protected] |