CVE-2023-53269 block: ublk: make sure that block size is set correctly
An attacker can cause a kernel panic by providing an invalid block size to the ublk driver, leading to a 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-2023-53269?
CVE-2023-53269 is a medium-severity denial of service vulnerability in Linux kernel, published on 16 Sep 2025. 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:
block: ublk: make sure that block size is set correctly
block size is one very key setting for block layer, and bad block size could panic kernel easily.
Make sure that block size is set correctly.
Meantime if ublk_validate_params() fails, clear ub->params so that disk is prevented from being added.
Which versions are affected by CVE-2023-53269?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53269?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-53269 being exploited?
There is no known exploitation of CVE-2023-53269 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53269, DEBIAN-CVE-2023-53269, GHSA-q6pc-2x62-x53v, UBUNTU-CVE-2023-53269.