---
title: "CVE-2026-93520: X.org X server & XWayland - Buffer Overflow"
description: "X.org X server < 2.1.25 and XWayland < 24.1.14 contain a heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange, letting authenticated X clients crash or execute code in server context."
url: https://panop.io/threat-heartbeat/CVE-2026-93520/
---

# CVE-2026-93520 X.org X server & XWayland - Buffer Overflow

X.org X server < 2.1.25 and XWayland < 24.1.14 contain a heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange, letting authenticated X clients crash or execute code in server context.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-93520)

## Details

Type

Buffer Overflow

Impact

Remote Code Execution, Denial Of Service

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

28 October 2026

Updated

29 October 2026

Weakness

[CWE-122](https://cwe.mitre.org/data/definitions/122.html)

## Vendor fix

Update to X.org X server 2.1.25 and XWayland 24.1.14 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-93520](https://nvd.nist.gov/vuln/detail/CVE-2026-93520)
- [https://gitlab.freedesktop.org/xorg/xserver/-/commit/b941a473e06f26a407a9adb15759be79f7418e86](https://gitlab.freedesktop.org/xorg/xserver/-/commit/b941a473e06f26a407a9adb15759be79f7418e86)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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