CVE-2018-5114: Canonical Ubuntu Linux

Medium severity, CVSS 5.3. EPSS: 1.6% chance of exploitation in the next 30 days.

If an existing cookie is changed to be "HttpOnly" while a document is open, the original value remains accessible through script until that document is closed. Network requests correctly use the changed HttpOnly cookie. 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.