CVE-2018-5153: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 1.7% chance of exploitation in the next 30 days.

If websocket data is sent with mixed text and binary in a single message, the binary data can be corrupted. This can result in an out-of-bounds read with the read memory sent to the originating server in response. This vulnerability affects Firefox < 60.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 17.10 only; version 18.04 only
• Mozilla Firefox: before 60.0 (fixed in 60.0)

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