Vulnerability · Published Jul 20, 2026 · Assigned by GitHub_M
CVE-2026-35198HeyForm vulnerable to stored XSS via form field titles
Critical 9.0
In plain English
A critical-severity cross-site scripting in heyform from heyform. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).
Severity (CVSS 3.1)9.0Critical
Exploit odds (30 days)0.5%top 57.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
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.
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H