CVE-2026-98691 thunderbolt: Tear down inactive DP tunnels when the domain is stopped
A use-after-free in the Linux kernel Thunderbolt driver allows local attackers to cause a denial of service or potentially execute code by triggering a race condition during domain teardown.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98691?
CVE-2026-98691 is an use after free 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: Tear down inactive DP tunnels when the domain is stopped
tb_stop() only tears down DMA tunnels so a DP tunnel that is still waiting for dprx_work to complete keeps that work queued while the routers are removed and the control channel is stopped. The work only stops once the DPRX timeout has passed and because it requeues itself until then the flush_workqueue() in tb_domain_remove() won't wait for its final run. The callback then runs against a domain that is already torn down. A reference to that domain is kept so the completion waiting for that domain to disappear in unbind will block until the timeout is eventually reached.
Tear down DP tunnels that are not active yet as well which also cancels that work. Tunnels for displays that are already alive are untouched and keep working.
Which versions are affected by CVE-2026-98691?
How do I fix CVE-2026-98691?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-98691 being exploited?
There is no known exploitation of CVE-2026-98691 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98691, DEBIAN-CVE-2026-98691, GHSA-7w6x-49rw-4c9g, UBUNTU-CVE-2026-98691.