CVE-2026-45797

Summary

HeyForm is an open-source form builder. Prior to version 3.0.0-rc.7, the /api/upload endpoint allows unauthenticated file uploads including SVG files. Uploaded SVGs are stored in the static assets directory and served with Content-Type: image/svg+xml by Express's serve-static middleware, allowing an attacker to achieve stored cross-site scripting (XSS) on the heyform domain without any authentication. Version 3.0.0-rc.7 contains a patch for the issue.

Affected Software

VendorProductVersion RangeStatus
heyformheyform< 3.0.0-rc.7affected

Weaknesses

  • CWE-79: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-434: CWE-434: Unrestricted Upload of File with Dangerous Type

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References