CVE-2023-1393: Fedoraproject Fedora

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

A flaw was found in X.Org Server Overlay Window. A Use-After-Free may lead to local privilege escalation. If a client explicitly destroys the compositor overlay window (aka COW), the Xserver would leave a dangling pointer to that window in the CompScreen structure, which will trigger a use-after-free later.

Affected products

• Fedoraproject Fedora: version 36 only; version 37 only; version 38 only
• X.org X Server: before 21.1.8 (fixed in 21.1.8)

Published 2023-03-30. Last modified 2026-06-17.