CVE-2026-35198: Heyform

Critical severity, CVSS 9.0. EPSS: 0.5% chance of exploitation in the next 30 days.

HeyForm is an open-source form builder. Prior to version 3.0.0-rc.7, a stored cross-site scripting (XSS) vulnerability in the form builder allows a low-privileged team member to inject malicious JavaScript that executes when a team owner views the form, leading to complete account takeover through privilege escalation. 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 2026-08-21.