CVE-2026-43255 wifi: libertas: fix WARNING in usb_tx_block
A race condition in the Libertas Wi-Fi driver allows triggering a kernel warning and potential denial of service by submitting USB requests concurrently.
- 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-2026-43255?
CVE-2026-43255 is a medium-severity vulnerability in Linux kernel, published on 6 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:
wifi: libertas: fix WARNING in usb_tx_block
The function usb_tx_block() submits cardp->tx_urb without ensuring that any previous transmission on this URB has completed. If a second call occurs while the URB is still active (e.g. during rapid firmware loading), usb_submit_urb() detects the active state and triggers a warning: 'URB submitted while active'.
Fix this by enforcing serialization: call usb_kill_urb() before submitting the new request. This ensures the URB is idle and safe to reuse.
Which versions are affected by CVE-2026-43255?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43255?
Apply the vendor's patch.
Is CVE-2026-43255 being exploited?
There is no known exploitation of CVE-2026-43255 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43255, DEBIAN-CVE-2026-43255, GHSA-w929-9wq4-xrmp, ROOT-OS-DEBIAN-11-CVE-2026-43255, ROOT-OS-UBUNTU-2204-CVE-2026-43255, ROOT-OS-UBUNTU-2404-CVE-2026-43255 and 1 more.