CVE-2017-16030: Useragent Project Useragent

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

Useragent is used to parse useragent headers. It uses several regular expressions to accomplish this. An attacker could edit their own headers, creating an arbitrarily long useragent string, causing the event loop and server to block. This affects Useragent 2.1.12 and earlier.

Affected products

• Useragent Project Useragent: up to and including 2.1.12

Published 2018-06-04. Last modified 2026-06-17.