CVE-2025-23167 Information

Description

A flaw in Node.js 20’s HTTP parser allows improper termination of HTTP/1 headers using \r\n\rX instead of the required \r\n\r\n. This inconsistency enables request smuggling allowing attackers to bypass proxy-based access controls and submit unauthorized requests.

The issue was resolved by upgrading llhttp to version 9 which enforces correct header termination.

Impact: This vulnerability affects only Node.js 20.x users prior to the llhttp v9 upgrade.

Reference

https://nodejs.org/en/blog/vulnerability/may-2025-security-releases