---
id: "CVE-2026-98696"
kind: "vulnerability"
aliases: ["CVE-2026-98696"]
title: "Linux kernel: USB serial driver unload order causes use-after-free"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kernel", "linux", "self-hosted", "usb-serial"]
not_affected_if: ["no-usb-serial-modules"]
published_at: "2026-10-18T16:17:23+00:00"
first_seen_at: "2026-10-23T21:57:16+00:00"
updated_at: "2026-10-25T05:19:00+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98696", "first_seen_at": "2026-10-23T21:57:16+00:00"}]
---

# Linux kernel: USB serial driver unload order causes use-after-free

Unloading a USB serial driver module deregisters the port drivers before the USB driver, so I/O can still run against freed port data. The sources do not say what an attacker gains beyond a crash or memory corruption.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- `uname -r` to see the running kernel version
- `lsmod | grep -i usbserial` to see whether USB serial driver modules are loaded
- unknown for a definitive check against a fixed kernel version

## Fix

- Update to a Linux kernel build that includes the upstream commit fixing USB serial driver deregistration order (version unknown from the sources)
- Check your distribution's kernel advisory for the patched package

## Timeline

- 2026-10-23T21:57:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98696

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

USB: serial: fix driver deregistration order

USB serial driver modules register one driver for the USB bus and one or
more drivers for the ports on the USB serial bus.

When unloading a driver module, the USB driver must be deregistered
before the USB serial bus drivers so that I/O is stopped before
unbinding the ports to avoid use-after-free in completion handlers
accessing port data.

Note that the "new_id" attributes must first be removed to prevent new
ids from being added and triggering a probe of the USB driver after it
has been deregistered.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_