CVE-2026-45797: medium-severity vulnerability in heyform
HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.4epss 0.6%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Affected products
heyform · heyformRelated CVEs — heyform
In the same product, most dangerous first.
CVE-2026-82291HIGHHeyForm Reflects Any Origin in CORS Responses While Allowing CredentialsEPSS 0.6%CVE-2026-63429HIGHHeyForm has unauthenticated /api/upload endpoint that accepts arbitrary files with no auth/session/form contextEPSS 0.5%CVE-2026-35198CRITICALHeyForm vulnerable to stored XSS via form field titlesEPSS 0.5%CVE-2026-63428MEDIUMHeyForm: completeSubmission persists submitter-supplied hidden fields verbatim without validating against the form's declared hidden-field setEPSS 0.3%CVE-2026-102615HIGHHeyForm: Uploaded HTML files are served as text/html on the app origin with no CSP — stored XSSEPSS —