HeyForm vulnerabilities

HeyForm prior to version 3.0.0-rc.7 contains a stored XSS vulnerability in the form builder. A low-privileged team member can inject malicious JavaScript that executes when a team owner views the form, leading to complete account takeover through privilege escalation.

HeyForm before 3.0.0-rc.8 reflects the request Origin header in CORS responses while allowing credentials, enabling cross-origin requests with authentication. Attackers can execute authenticated GraphQL queries from malicious pages visited by logged-in users to access workspaces, projects, forms, submissions, and respondent data, or modify account settings.

Vulnerability in HeyForm before version 3.0.0-rc.9: the POST /api/upload endpoint lacks authentication and form-context validation. Any anonymous user can upload a file (up to 10 MB) and receive a public URL.

HeyForm before version 3.0.0-rc.9 does not properly validate `hiddenFields` submitted by users. An anonymous user can inject arbitrary key-value pairs, including XSS payloads, which are then forwarded to webhooks.

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.