CVE-2026-66062

MEDIUM
MEDIUM Priority: 0.03 BB Relevance: 71/100
Published: 2026-08-07 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: None
I: None
A: Low

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.

Weakness Classification (1)

Bug Bounty Relevance

71 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

5.3 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploitation Probability

0.51%
Raw Score 0.005070
Percentile 43.2%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00507
2026-10-28
0.00507

Intelligence Sources

nvd ref →