CVE-2026-31701 ALSA: caiaq: take a reference on the USB device in create_card()
A use-after-free vulnerability in the Linux kernel ALSA caiaq driver allows attackers to cause a denial of service or potentially execute code via improper USB device reference handling.
- 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-2026-31701?
CVE-2026-31701 is a medium-severity use after free vulnerability in Linux kernel, published on 1 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:
ALSA: caiaq: take a reference on the USB device in create_card()
The caiaq driver stores a pointer to the parent USB device in cdev->chip.dev but never takes a reference on it. The card's private_free callback, snd_usb_caiaq_card_free(), can run asynchronously via snd_card_free_when_closed() after the USB device has already been disconnected and freed, so any access to cdev->chip.dev in that path dereferences a freed usb_device.
On top of the refcounting issue, the current card_free implementation calls usb_reset_device(cdev->chip.dev). A reset in a free callback is inappropriate: the device is going away, the call takes the device lock in a teardown context, and the reset races with the disconnect path that the callback is already cleaning up after.
Take a reference on the USB device in create_card() with usb_get_dev(), drop it with usb_put_dev() in the free callback, and remove the usb_reset_device() call.
Which versions are affected by CVE-2026-31701?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31701?
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-2026-31701 being exploited?
There is no known exploitation of CVE-2026-31701 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-31701, DEBIAN-CVE-2026-31701, GHSA-pf8h-4wmf-9gv4, ROOT-OS-DEBIAN-11-CVE-2026-31701, ROOT-OS-DEBIAN-12-CVE-2026-31701, ROOT-OS-UBUNTU-2204-CVE-2026-31701 and 2 more.