File Upload Vulnerability in HeyForm Open-Source Form Builder
CVE-2026-45797

6.4MEDIUM

Key Information:

Vendor

Heyform

Status
Heyform
Vendor
CVE Published:
20 July 2026

What is CVE-2026-45797?

HeyForm, a widely used open-source form builder, presents a security risk prior to version 3.0.0-rc.7 due to its /api/upload endpoint. This endpoint allows unauthenticated users to upload files, particularly SVG files, which are stored in the static assets directory. Once uploaded, these SVG files are served with the Content-Type: image/svg+xml via Express's serve-static middleware. This behavior enables potential attackers to execute stored cross-site scripting (XSS) attacks on the HeyForm domain without requiring authentication. The vulnerability has been addressed in version 3.0.0-rc.7, which includes necessary patches to enhance security.

Affected Version(s)

heyform < 3.0.0-rc.7

References

https://github.com/heyform/heyform/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/heyform/heyform/commit/144240e5545d10f...
x_refsource_MISC

CVSS V4

Score:
6.4
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.