CVE-2020-13974: Canonical Ubuntu Linux

High severity, CVSS 7.8. EPSS: 0.6% chance of exploitation in the next 30 days.

An issue was discovered in the Linux kernel 4.4 through 5.7.1. drivers/tty/vt/keyboard.c has an integer overflow if k_ascii is called several times in a row, aka CID-b86dab054059. NOTE: Members in the community argue that the integer overflow does not lead to a security issue in this case.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 18.04 only; version 20.04 only
• Debian Debian Linux: version 9.0 only
• Linux Linux Kernel: before 4.4.227 (fixed in 4.4.227); from 4.5, before 4.9.227 (fixed in 4.9.227); from 4.10, before 4.14.184 (fixed in 4.14.184); from 4.15, before 4.19.128 (fixed in 4.19.128); from 4.20, before 5.4.46 (fixed in 5.4.46); from 5.5, before 5.6.18 (fixed in 5.6.18); …

Published 2020-06-09. Last modified 2026-06-17.