CVE-2026-43431 xhci: Fix NULL pointer dereference when reading portli debugfs files

Medium 5.5 Published Updated

A NULL pointer dereference in the Linux kernel xhci driver can cause a system crash when reading specific debugfs files.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2026-43431?

CVE-2026-43431 is a medium-severity vulnerability in Linux kernel, published on 8 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

xhci: Fix NULL pointer dereference when reading portli debugfs files

Michal reported and debgged a NULL pointer dereference bug in the recently added portli debugfs files

Oops is caused when there are more port registers counted in xhci->max_ports than ports reported by Supported Protocol capabilities. This is possible if max_ports is more than maximum port number, or if there are gaps between ports of different speeds the 'Supported Protocol' capabilities.

In such cases port->rhub will be NULL so we can't reach xhci behind it. Add an explicit NULL check for this case, and print portli in hex without dereferencing port->rhub.

Weakness: CWE-476

Which versions are affected by CVE-2026-43431?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-43431?

Apply the vendor's patch.

Is CVE-2026-43431 being exploited?

There is no known exploitation of CVE-2026-43431 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as DEBIAN-CVE-2026-43431, GHSA-q7mh-rc36-3j7h, UBUNTU-CVE-2026-43431.

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