CVE-2026-45797
HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload
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.
- Record
CVE-2026-45797- CVSS 4.0
- 6.4 Medium
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 - Weakness
- CWE-79, CWE-434
- Updated
- 2026-11-02
EUVDEUVD-2026-45983
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.
- Record
EUVD-2026-45983- CVSS 4.0
- 6.4 Medium
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 - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-45797- CVSS 4.0
- 6.4 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-79, CWE-434
- Updated
- 2026-11-02
OSV
HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload
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.
- Record
CVE-2026-45797- CVSS 4.0
- 6.4 Medium
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 - Weakness
- CWE-434, CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-45797 is a medium vulnerability (CVSS 6.4) in Heyform, published July 20, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.57%, the 47th percentile. No source names a fixed version.