GitHub Advisoryadvisory · npm

GHSA-29g2-3rmr-qm68 SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header

MEDIUM Published 2026-08-07 Modified 2026-08-07 Official page ↗
Aliases
CVE-2026-66062
Ecosystem
npm
Packages
@sveltejs/kit
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weaknesses
CWE-1333
Reviewed
2026-08-07

Affected packages

• npm @sveltejs/kit: < 2.70.2 → fixed in 2.70.2

Description

Impact SvelteKit is vulnerable to remote CPU-exhaustion DoS attacks via specifically-crafted `Accept` headers. The impact is mitigated by default header length limits on most platforms, but in the case of raised or absent limits a denial of service is possible. Patches The vulnerability is patched in `@sveltejs/kit` version 2.70.2.

Related

Alias · CVE (1)

  • CVE-2026-66062 SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. vulnerability

Weakness · CWE (1)

  • CWE-1333 Inefficient Regular Expression Complexity weakness

References