CVE-2018-15857: Canonical Ubuntu Linux

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

An invalid free in ExprAppendMultiKeysymList in xkbcomp/ast-build.c in xkbcommon before 0.8.1 could be used by local attackers to crash xkbcommon keymap parsers or possibly have unspecified other impact by supplying a crafted keymap file.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 18.04 only
• Xkbcommon Libxkbcommon: before 0.8.1 (fixed in 0.8.1)
• Xkbcommon Xkbcommon: before 0.8.1 (fixed in 0.8.1)

Published 2018-08-25. Last modified 2026-06-17.