---
title: ZES Kernel Update for CVE-2026-98432
description: This support article explains how to install the critical kernel security update for CVE-2026-98432 on Zello Enterprise Server 2025 and 2026.
---

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November 9, 2026

# ZES Kernel Update for CVE-2026-98432

This article is written for: ✅ Zello Work ❌ Zello Friends & Family.

This document provides guidance for installing a Critical kernel security update that was released in November 2026 on ZES 2025 and ZES 2026.

### About the vulnerability

CVE-2026-98432 is a Critical-rated vulnerability in the Linux kernel, which Zello Enterprise Server (ZES) runs on. Risk to ZES is lower than that rating suggests, because the only currently known exploit requires Multipath TCP (MPTCP) to be enabled, and MPTCP isn’t enabled on ZES.

### Update process

These steps have been validated on ZES 2025 and ZES 2026. If you are running an older version of ZES, please migrate to a newer version first.

**Note:** This update requires a reboot of the ZES server, which will result in 5-10 minute downtime.

These steps also require internet access from ZES to download the update packages.

1. Take a VM snapshot or backup of the ZES host.
2. Note your current kernel version so you can compare it afterwards:
   
   ```
   uname -r 
   ```
3. Install the updated kernel:
   
   ```
   sudo dnf config-manager --set-disabled cloud-kernel 2>/dev/null || truesudo dnf upgrade --disableexcludes=baseos 'kernel*' 
   ```
4. Reboot the server to load the new kernel. ZES starts automatically after the reboot:
   
   ```
   sudo reboot 
   ```

If the server doesn't come back up as expected, restore the snapshot from step 1 and contact Zello Support.

### Confirm the update

After the reboot, check the running kernel:

```
uname -r
```

The version must match or be newer than kernel-4.18.0-553.182.1.el8\_10.x86\_64

Then confirm that ZES is running and that users can sign in and talk on a test channel.

### Need help?

Contact Zello Support if you have questions, can't install the update, or see problems after the reboot. Include your ZES version, any error messages you got during the upgrade process, and the output of uname -r.

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