CVE-2026-45797 | HeyForm is an open-source form builder. Prior to version 3.0… | CVSS 6.4 MEDIUM

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.

Metadata

CVE ID: CVE-2026-45797
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-05-13 08:19 UTC
Published: 2026-07-20 15:43 UTC
Last updated: 2026-07-20 19:07 UTC
Primary CWE: CWE-79
CWE-79: Improper Neutralization of Input During Web Page Gen…
Vendor / Product: heyform / heyform
Sources: cve.org · NVD

Severity & Metrics

6.4 MEDIUM CVSS 4.0

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

SSVC — CISA Coordinator

Exploitation: none
Automatable: yes
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
heyform	heyform	—	< 3.0.0-rc.7

Weakness (CWE)

CWE	Source	Description
CWE-434	cna	CWE-434: Unrestricted Upload of File with Dangerous Type
CWE-79	cna	CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS scores (1)

Score	Severity	Version	Source	Vector
6.4	MEDIUM	4.0	cna	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 (2)

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