CVE-2026-66062

medium

Description

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.70.2, the content negotiation header parser used by SvelteKit's request handling (for headers such as Accept) uses a regular expression vulnerable to quadratic backtracking, so a maliciously crafted header value can cause excessive CPU consumption and degrade or deny service. Version 2.70.2 fixes the issue.

References

https://github.com/sveltejs/kit/security/advisories/GHSA-29g2-3rmr-qm68

https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]

https://github.com/sveltejs/kit/commit/82712fc02c24b1dcf5b25d7a52129cd8455f04f5

Details

Source: Mitre, NVD

Published: 2026-08-07

Updated: 2026-08-07

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 5.3

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Severity: Medium

EPSS

EPSS: 0.00291