CVE-2026-90324 ublk: check import_ubuf() return value
A missing return value check in the Linux kernel ublk driver can lead to a null pointer dereference and system crash.
- 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-2026-90324?
CVE-2026-90324 is a high-severity vulnerability in Linux, published on 17 Sep 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:
ublk: check import_ubuf() return value
import_ubuf() can fail if the address range (provided by the userspace ublk server) is outside the allowed user address space. Return that 0 bytes were copied if import_ubuf() fails rather than passing an uninitialized struct iov_iter to ublk_copy_user_pages().
Which versions are affected by CVE-2026-90324?
How do I fix CVE-2026-90324?
Apply the vendor's patch.
Is CVE-2026-90324 being exploited?
There is no known exploitation of CVE-2026-90324 in the wild and no public exploit code.
Sources
Also known as AZL-101900, BELL-CVE-2026-90324, DEBIAN-CVE-2026-90324, GHSA-9f96-m8pp-q99r, UBUNTU-CVE-2026-90324.