CVE-2026-66062
SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header
- State
- Published
- Severity
- 5.3 Medium
- Published
- Aug 7, 2026
- Updated
- Aug 7, 2026
- Reserved
- Jul 23, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | GitHub_M |
Weaknesses
- CWE-1333 Inefficient Regular Expression Complexity
Affected Products
| Product | Versions |
|---|---|
kitsveltejs |
|
References
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