CVE-2026-63429
HeyForm has unauthenticated /api/upload endpoint that accepts arbitrary files with no auth/session/form context
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
HeyForm has unauthenticated /api/upload endpoint that accepts arbitrary files with no auth/session/form context
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.
- Record
CVE-2026-63429- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-306, CWE-434
- Updated
- 2026-11-02
EUVDEUVD-2026-45986
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.
- Record
EUVD-2026-45986- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-63429- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-306, CWE-434
- Updated
- 2026-11-02
OSV
HeyForm has unauthenticated /api/upload endpoint that accepts arbitrary files with no auth/session/form context
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.
- Record
CVE-2026-63429- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-306, CWE-434
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-63429 is a high vulnerability (CVSS 8.6) in Heyform, published July 20, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.51%, the 43rd percentile. No source names a fixed version.