CVE-2016-10539: Negotiator Project Negotiator

High severity, CVSS 7.5. EPSS: 1.4% chance of exploitation in the next 30 days.

negotiator is an HTTP content negotiator for Node.js and is used by many modules and frameworks including Express and Koa. The header for "Accept-Language", when parsed by negotiator 0.6.0 and earlier is vulnerable to Regular Expression Denial of Service via a specially crafted string.

Affected products

• Negotiator Project Negotiator: up to and including 0.6.0

Published 2018-05-31. Last modified 2026-06-17.