# CVE-2026-45797: HeyForm unauthenticated stored XSS via SVG file upload

Source: https://junglewise.ai/threats/cve-2026-45797-heyform-unauthenticated-stored-xss-via-svg-file-upload  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-20. Updated: 2026-07-20  
License: CC BY 4.0 with a link back

CVE-2026-45797 · Severity: info · CVSS 6.4 · Published 2026-07-20

HeyForm is an open-source platform used for building and managing online forms. A security flaw allows anyone on the internet to upload malicious files to the server without needing an account. If a user or administrator views one of these files, an attacker could steal their login session, take over their account, or access sensitive form data.

Technologies: [HeyForm](https://junglewise.ai/threats/technologies/heyform). Vendors: [HeyForm](https://junglewise.ai/threats/vendors/heyform).

## Quick answers

**Is CVE-2026-45797 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45797 being exploited in the wild.

**How severe is CVE-2026-45797?** Informational severity, with a CVSS score of 6.4, published 20 July 2026.

**Which products and versions are affected?** HeyForm < 3.0.0-rc.7.

**Is there a fix for CVE-2026-45797?** A patch was published on 2026-07-20: Fix confirmed in version 3.0.0-rc.7 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45797 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-45797?** Check whether you run HeyForm at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

HeyForm prior to version 3.0.0-rc.7 contains a stored cross-site scripting (XSS) vulnerability due to unrestricted file uploads. The `/api/upload` endpoint lacks an `@Auth()` decorator, allowing unauthenticated users to upload SVG files. Because the application's Express `serve-static` middleware serves these files with the `image/svg+xml` MIME type, any embedded JavaScript within the SVG is executed in the context of the victim's browser session when the file is accessed. This allows attackers to perform actions on behalf of users, such as stealing session cookies or executing GraphQL mutations. The issue is fixed in version 3.0.0-rc.7 by blocking SVG uploads and hardening the static file serving configuration.

## Affected products

- HeyForm HeyForm < 3.0.0-rc.7

## Timeline

- 2026-05-14: advisory: GitHub Security Advisory published
- 2026-07-20: disclosed: CVE published to NVD
- 2026-07-20: patched: Fix confirmed in version 3.0.0-rc.7

## References

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

## Related threats

- [HeyForm stored cross-site scripting in file upload](https://junglewise.ai/threats/cve-2026-102615-heyform-is-an-open-source-form-builder-prior-to-3-0-1-api-upload)
- [HeyForm CORS misconfiguration with credential handling](https://junglewise.ai/threats/cve-2026-82291-heyform-cors-misconfiguration-with-credential-handling)
- [HeyForm missing authentication in file upload API](https://junglewise.ai/threats/cve-2026-63429-heyform-missing-authentication-in-file-upload-api)
- [HeyForm improper input validation in hiddenFields submission](https://junglewise.ai/threats/cve-2026-63428-heyform-improper-input-validation-in-hiddenfields-submission)
- [HeyForm stored XSS in form builder field titles](https://junglewise.ai/threats/cve-2026-35198-heyform-stored-xss-in-form-builder-field-titles)