CVE-2018-15862: Canonical Ubuntu Linux

Medium severity, CVSS 5.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Unchecked NULL pointer usage in LookupModMask in xkbcomp/expr.c in xkbcommon before 0.8.2 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file with invalid virtual modifiers.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 18.04 only
• Xkbcommon Libxkbcommon: up to and including 0.8.1
• Xkbcommon Xkbcommon: up to and including 0.8.1

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