Vulnerability · Published Jan 15, 2026 · Assigned by GitHub_M

CVE-2026-22803SvelteKit has a memory amplification DoS in Remote Functions binary form deserializer

High 8.2

In plain English

A high-severity security flaw in kit from sveltejs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.2High
Exploit odds (30 days)0.6%top 51.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. From 2.49.0 to 2.49.4, the experimental form remote function uses a binary data format containing a representation of submitted form data. A specially-crafted payload can cause the server to allocate a large amount of memory, causing DoS via memory exhaustion. This vulnerability is fixed in 2.49.5.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npm@sveltejs/kit2.49.5GHSA-j2f3-wq62-6q46

Affected products (as reported)

VendorProductVersions
sveltejs kit >= 2.49.0, < 2.49.5

Weakness: CWE-789 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References