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

> An attacker can upload malicious SVG files to trigger stored XSS on the HeyForm domain without authentication, potentially compromising user sessions.

- **Severity:** Medium 6.4 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 20 Jul 2026
- **Updated:** 20 Jul 2026
- **Also known as:** GHSA-m94h-jxvc-hhch

## What is CVE-2026-45797?

CVE-2026-45797 is a medium-severity cross-site scripting vulnerability in heyform, published on 20 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2026-45797?


## How do I fix CVE-2026-45797?

No fix has been published for CVE-2026-45797 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-45797 being exploited?

There is no known exploitation of CVE-2026-45797 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45797 and fix it if it is affected.

What it is: CVE-2026-45797 is a medium-severity cross-site scripting vulnerability in heyform, published on 20 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-45797 in the wild and no public exploit code.

Affected product: heyform. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-45797/ (Markdown: https://insights.sbomify.com/CVE-2026-45797/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45797
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45797
- OSV: https://osv.dev/vulnerability/CVE-2026-45797

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45797/
Summaries are generated and may contain mistakes; the official description above is the record.