CVE-2026-64340 USB: legousbtower: fix use-after-free on disconnect race
A race condition in the Linux kernel's legousbtower USB driver allows attackers to trigger a use-after-free, potentially leading to code execution or privilege escalation.
- 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-2026-64340?
CVE-2026-64340 is a high-severity use after free vulnerability in Linux kernel, published on 25 Jul 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: legousbtower: fix use-after-free on disconnect race
mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects directly (unlike spinlocks and refcounts). [1][2]
Use a kref to release the driver data to avoid use-after-free in mutex_unlock() when release() races with disconnect().
[1] a51749ab34d9 ("locking/mutex: Document that mutex_unlock() is non-atomic") [2] 2b9d9e0a9ba0 ("locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after it's unlocked")
Weakness: CWE-416
Which versions are affected by CVE-2026-64340?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64340?
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-2026-64340 being exploited?
There is no known exploitation of CVE-2026-64340 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-64340, DEBIAN-CVE-2026-64340, GHSA-p757-fg2x-77h8, ROOT-OS-UBUNTU-2204-CVE-2026-64340, UBUNTU-CVE-2026-64340.