CVE-2026-45975 ublk: use READ_ONCE() to read struct ublksrv_ctrl_cmd
A race condition in the Linux kernel ublk driver allows concurrent userspace writes to corrupt kernel state, potentially leading to undefined behavior.
- 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-2026-45975?
CVE-2026-45975 is a medium-severity vulnerability in Linux kernel, published on 27 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:
ublk: use READ_ONCE() to read struct ublksrv_ctrl_cmd
struct ublksrv_ctrl_cmd is part of the io_uring_sqe, which may lie in userspace-mapped memory. It's racy to access its fields with normal loads, as userspace may write to them concurrently. Use READ_ONCE() to copy the ublksrv_ctrl_cmd from the io_uring_sqe to the stack. Use the local copy in place of the one in the io_uring_sqe.
Which versions are affected by CVE-2026-45975?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-45975?
Apply the vendor's patch.
Is CVE-2026-45975 being exploited?
There is no known exploitation of CVE-2026-45975 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as GHSA-3q42-3w8p-xmr3, UBUNTU-CVE-2026-45975.