GHSA-pfhg-q3qv-9q6r
SvelteKit: URL redirection to untrusted site via enhanced form submission
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @sveltejs/kit | < 3.0.0 | 3.0.0 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
Applications using enhanced form actions (`use:enhance`) on routes that accept paths beginning with `//`, such as catch-all routes, may be vulnerable to an open redirect.
### Patches
A fix has been prepared for `@sveltejs/kit` 3.0.0. Users should upgrade to 3.0.0 or later.
The fix preserves leading double slashes in action paths without generating protocol-relative URLs, restricts non-redirect action navigation to the current origin, and includes the origin when comparing action locations with the current page.
### Workarounds
Reject requests whose parsed URL pathname begins with `//` before route resolution, for example in a reverse proxy or a SvelteKit `handle` hook.
Alternatively, disable navigation for non-redirect enhanced form results by supplying a custom submission callback:
```svelte
<form method="POST" use:enhance={() => ({ update }) => update({ navigate: false })}>
<!-- form fields -->
</form>
```
This applies non-redirect results to the current page instead of navigating to the action location.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/sveltejs/kit/security/advisories/GHSA-pfhg-q3qv-9q6r
- https://nvd.nist.gov/vuln/detail/CVE-2026-114060
- https://github.com/sveltejs/kit/commit/91aae3547c6cd2935d79c09a53e27c740100000a
- https://github.com/sveltejs/kit
- https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]
- https://www.vulncheck.com/advisories/sveltekit-before-3.0.0-open-redirect-via-enhanced-form-actions