Heyform vulnerabilities

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Published CVEs affecting Heyform products: 5 record(s), with severity, exploitation and fixes.

Exploited only (KEV) →

CVE-2026-82291 High · 8.1 CWE-942 Aug 28, 2026

HeyForm Reflects Any Origin in CORS Responses While Allowing Credentials

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.

CVE-2026-63429 High · 8.6 CWE-306 Jul 20, 2026

HeyForm has unauthenticated /api/upload endpoint that accepts arbitrary files with no auth/session/form context

HeyForm is an open-source form builder. Prior to version 3.0.0-rc.9, `POST /api/upload` has no authentication guard, no global guard, no form-context validation, no `openToken` requirement, and no session cookie check. Any anonymous internet user can upload files (PDF, DOC/DOCX, XLS/XLSX, CSV, TXT, MP4, images, etc., up to 10 MB) and receive a permanent public URL on the HeyForm domain. The endpoint is used by both authenticated form creators and unauthenticated form submitters; because no form-context binding exists, every request to it is anonymously accepted. Version 3.0.0-rc.9 contains a patch for the issue.

CVE-2026-63428 Medium · 5.8 CWE-20 Jul 20, 2026

HeyForm: completeSubmission persists submitter-supplied hidden fields verbatim without validating against the form's declared hidden-field set

HeyForm is an open-source form builder. Prior to version 3.0.0-rc.9, `completeSubmission` accepts a `hiddenFields: [{id, name, value}]` array from the submitter and stores it verbatim in `submission.hiddenFields`, without validating the supplied `id`/`name` against the form's declared `form.hiddenFields` schema. An anonymous form submitter can therefore inject arbitrary key/value pairs (including XSS payloads, fake authorization metadata, integration-relevant values) into the stored submission. These fields are subsequently forwarded as-is to every webhook integration registered on the form. Version 3.0.0-rc.9 contains a patch for the issue.

CVE-2026-45797 Medium · 6.4 CWE-79 Jul 20, 2026

HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload

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.

CVE-2026-35198 Critical · 9.0 CWE-79 Jul 20, 2026

HeyForm vulnerable to stored XSS via form field titles

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.