CVE-2023-1393
xorg-x11-server: X.Org Server Overlay Window Use-After-Free Local Privilege Escalation Vulnerability
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 29, 2023
Updated · November 21, 2025
Description
A vulnerability was found in X.Org Server. This flaw occurs if a client explicitly destroys the compositor overlay window (aka COW), where Xserver leaves a dangling pointer to that window in the CompScreen structure, which will later trigger a use-after-free issue. The Overlay Window use-after-free issue can lead to a local privilege escalation vulnerability.
Statement
Xorg server does not run with root privileges in Red Hat Enterprise Linux 8 and 9. Therefore, Red Hat Enterprise Linux 8 and 9 have been rated Moderate severity.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 · Use After Free