CVE-2018-12401: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 2.5% chance of exploitation in the next 30 days.

Some special resource URIs will cause a non-exploitable crash if loaded with optional parameters following a '?' in the parsed string. This could lead to denial of service (DOS) attacks. This vulnerability affects Firefox < 63.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 18.04 only; version 18.10 only
• Mozilla Firefox: before 63.0 (fixed in 63.0)

Published 2019-02-28. Last modified 2026-06-17.