CVE-2026-40074: Svelte Kit

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.57.1, redirect, when called from inside the handle server hook with a location parameter containing characters that are invalid in a HTTP header, will cause an unhandled TypeError. This could result in DoS on some platforms, especially if the location passed to redirect contains unsanitized user input. This vulnerability is fixed in 2.57.1.

Affected products

• Svelte Kit: before 2.57.1 (fixed in 2.57.1)

Published 2026-04-10. Last modified 2026-06-17.