CVE-2026-98692 thunderbolt: Make the DP tunnel activation callback mandatory

What is CVE-2026-98692?

CVE-2026-98692 is a memory corruption vulnerability in Linux, published on 18 Oct 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:

thunderbolt: Make the DP tunnel activation callback mandatory

tb_tunnel_alloc_dp() takes an optional callback which is run from dprx_work once the DPRX capabilities read has completed. Without that callback tb_dp_dprx_start() reads the capabilities synchronously and never queues the work. It however always takes a tunnel reference which is only dropped by dprx_work itself or by tb_dp_dprx_stop() when cancel_delayed_work() actually canceled that work. That reference is thus leaked for every tunnel without a callback.

The only tunnels without one are those from tb_tunnel_discover_dp(), which are activated again when restoring from hibernation. Pass the callback to tb_tunnel_discover_dp() as well and drop the synchronous path such that the DPRX capabilities are always read from dprx_work. Hibernation restore then also no longer blocks for up to 12 seconds while waiting for that read to complete.

Also fix up the KUnit tests.

Which versions are affected by CVE-2026-98692?

How do I fix CVE-2026-98692?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-98692 being exploited?

There is no known exploitation of CVE-2026-98692 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-98692, DEBIAN-CVE-2026-98692, GHSA-j976-jwv6-gqm2, UBUNTU-CVE-2026-98692.