CVE-2026-63429 | HeyForm is an open-source form builder. Prior to version 3.0… | CVSS 8.6 HIGH

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.

Metadata

CVE ID: CVE-2026-63429
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-07-16 19:35 UTC
Published: 2026-07-20 15:54 UTC
Last updated: 2026-07-20 17:45 UTC
Primary CWE: CWE-306
CWE-306: Missing Authentication for Critical Function
Vendor / Product: heyform / heyform
Sources: cve.org · NVD

Severity & Metrics

8.6 HIGH CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: yes
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
heyform	heyform	—	< 3.0.0-rc.9

Weakness (CWE)

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

CVSS scores (1)

Score	Severity	Version	Source	Vector
8.6	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

References (2)

https://github.com/heyform/heyform/security/advisories/GHSA-432x-54v2-p7p7 https://github.com/heyform/heyform/security/advisories/GHSA-432x-54v2-p7p7
https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2 https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2