CVE-2026-43424 usb: gadget: f_tcm: Fix NULL pointer dereferences in nexus handling
A malicious USB host can trigger a kernel panic via NULL pointer dereference in the USB gadget target driver, causing local denial of service.
- 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-2026-43424?
CVE-2026-43424 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:
usb: gadget: f_tcm: Fix NULL pointer dereferences in nexus handling
The `tpg->tpg_nexus` pointer in the USB Target driver is dynamically managed and tied to userspace configuration via ConfigFS. It can be NULL if the USB host sends requests before the nexus is fully established or immediately after it is dropped.
Currently, functions like `bot_submit_command()` and the data transfer paths retrieve `tv_nexus = tpg->tpg_nexus` and immediately dereference `tv_nexus->tvn_se_sess` without any validation. If a malicious or misconfigured USB host sends a BOT (Bulk-Only Transport) command during this race window, it triggers a NULL pointer dereference, leading to a kernel panic (local DoS).
This exposes an inconsistent API usage within the module, as peer functions like `usbg_submit_command()` and `bot_send_bad_response()` correctly implement a NULL check for `tv_nexus` before proceeding.
Fix this by bringing consistency to the nexus handling. Add the missing `if (!tv_nexus)` checks to the vulnerable BOT command and request processing paths, aborting the command gracefully with an error instead of crashing the system.
Weakness: CWE-476
Which versions are affected by CVE-2026-43424?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43424?
Apply the vendor's patch.
Is CVE-2026-43424 being exploited?
There is no known exploitation of CVE-2026-43424 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43424, DEBIAN-CVE-2026-43424, GHSA-rx37-q58j-c4c7, ROOT-OS-DEBIAN-11-CVE-2026-43424, ROOT-OS-UBUNTU-2204-CVE-2026-43424, ROOT-OS-UBUNTU-2404-CVE-2026-43424 and 1 more.