SvelteKit: URL redirection to untrusted site via enhanced form submission
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:
<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.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @sveltejs/kit | < 3.0.0 | 3.0.0 |
References
- 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/kit@3.0.0
- https://www.vulncheck.com/advisories/sveltekit-before-3.0.0-open-redirect-via-enhanced-form-actions
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-601- Platform
- npm
- Package
@sveltejs/kit- Disclosed
- 23.10.2026
- Updated
- 24.10.2026 00:17
Sources and licenses
OSV / GitHub Advisory Database - GHSA-pfhg-q3qv-9q6r - CC BY 4.0
Vulnerability history: @sveltejs/kit
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 19
- First → latest
- 04.2023 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 6
- Medium 8
- Low 5
Disclosures per year
- 2023: 2
- 2024: 3
- 2025: 1
- 2026: 13
-
SvelteKit: URL redirection to untrusted site via enhanced form submission this entry
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