CVE-2026-45797: Heyform

Medium severity, CVSS 6.4. EPSS: 0.6% chance of exploitation in the next 30 days.

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 products

• Heyform Heyform: before 3.0.0-rc.7 (fixed in 3.0.0-rc.7)

Published 2026-07-20. Last modified 2026-07-22.