# CVE-2026-128120: SvelteKit: DoS while parsing form data from a remote functions `form`

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. From version 2.42.0 until 3.1.1, applications using the experimental remote functions flag and a remote form function could perform quadratic synchronous work while parsing a specially crafted request with many form entries. The parsing work could block the event loop for an extended period and deny service. This issue is fixed in 3.1.1.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- sveltejs / kit: >= 2.42.0, < 3.1.1 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-407

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/sveltejs/kit/security/advisories/GHSA-3r8g-jcqq-3p5j (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/sveltejs/kit/commit/24d8ee409d83c438330ff2850b4f159c1222aa27 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sveltejs/kit/releases/tag/@sveltejs/kit@3.1.1 (CNA: GitHub_M; x_refsource_MISC)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-128120; retrieved 2026-11-13; source updated 2026-11-13

Revision: feef9525fe4d2d192aad862bb4974163a8d6a861c79cec26c3877c72f5c900e0

Canonical: https://y2.dev/cve/CVE-2026-128120

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