What’s Vulnerable › Vulnerabilities

CVE-2026-45797: HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload

• Severity: medium (CVSS 6.4 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-20 · updated 2026-07-22
• Weakness: CWE-79

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.

Affected products

• heyform: before 3.0.0-rc.7

References

• https://github.com/heyform/heyform/commit/144240e5545d10fd9e120d05ccb402a6d7064674
• https://github.com/heyform/heyform/security/advisories/GHSA-m94h-jxvc-hhch

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