CVE-2018-5122: Canonical Ubuntu Linux

Critical severity, CVSS 9.8. EPSS: 2.8% chance of exploitation in the next 30 days.

A potential integer overflow in the "DoCrypt" function of WebCrypto was identified. If a means was found of exploiting it, it could result in an out-of-bounds write. This vulnerability affects Firefox < 58.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 17.10 only
• Mozilla Firefox: up to and including 57.0.4

Published 2018-06-11. Last modified 2026-06-17.