CVE-2026-63429

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

State: Published
Severity: 8.6 High
Published: Jul 20, 2026
Updated: Jul 20, 2026
Reserved: Jul 16, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	8.6 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L	GitHub_M

Weaknesses

CWE-306 Missing Authentication for Critical Function
CWE-434 Unrestricted Upload of File with Dangerous Type

Affected Products

Product	Versions
heyformheyform	< 3.0.0-rc.9Affected

References

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