Description
SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.49.5, SvelteKit is vulnerable to a server side request forgery (SSRF) and denial of service (DoS) under certain conditions. From 2.44.0 through 2.49.4, the vulnerability results in a DoS when your app has at least one prerendered route (export const prerender = true). From 2.19.0 through 2.49.4, the vulnerability results in a DoS when your app has at least one prerendered route and you are using adapter-node without a configured ORIGIN environment variable, and you are not using a reverse proxy that implements Host header validation. This vulnerability is fixed in 2.49.5.
Scores
CVSS v3
9.1
EPSS
0.0002
EPSS Percentile
5.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-248
CWE-918
Status
published
Products (4)
svelte/adapter-node
5.4.1 - 5.5.1
svelte/kit
2.19.0 - 2.49.5
sveltejs/adapter-node
5.4.1 - 5.5.1npm
sveltejs/kit
2.19.0 - 2.49.5npm
Published
Jan 15, 2026
Tracked Since
Feb 18, 2026