Vulnerability · Published Jul 20, 2026 · Assigned by GitHub_M

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

Medium 6.4

In plain English

A medium-severity cross-site scripting in heyform from heyform. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities).

Severity (CVSS 4.0)6.4Medium

Exploit odds (30 days)0.6%top 52.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
heyform	heyform	< 3.0.0-rc.7

Weakness: CWE-79, CWE-434 · 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

References

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