CVE-2026-45797

HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload

Published Jul 20, 2026 CVSS 4.0 · 6.4 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Heyform
Heyform heyform
Vendors & Products Heyform
Heyform heyform
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload
Weaknesses CWE-434
CWE-79
References
Metrics cvssV4_0

{'score': 6.4, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 20, 2026, 7:07 PM
Reserved
May 13, 2026, 8:19 AM
Status
Deferred
Published
Jul 20, 2026, 4:17 PM
Modified
Jul 22, 2026, 8:50 PM