CVE-2026-35198 HeyForm vulnerable to stored XSS via form field titles
A stored XSS vulnerability in HeyForm allows low-privileged users to inject scripts that execute for team owners, leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-35198?
CVE-2026-35198 is a critical cross-site scripting vulnerability in heyform, published on 20 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-35198?
How do I fix CVE-2026-35198?
No fix has been published for CVE-2026-35198 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-35198 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35198 exists.
Sources
Also known as GHSA-chmm-jqpm-3pwx.