CVE-2023-53506 udf: Do not bother merging very long extents
A bug in the Linux kernel UDF filesystem extent merging logic can corrupt file data, potentially leading to system instability or data loss.
- 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-2023-53506?
CVE-2023-53506 is a high-severity memory corruption vulnerability in Linux kernel, published on 1 Oct 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:
udf: Do not bother merging very long extents
When merging very long extents we try to push as much length as possible to the first extent. However this is unnecessarily complicated and not really worth the trouble. Furthermore there was a bug in the logic resulting in corrupting extents in the file as syzbot reproducer shows. So just don't bother with the merging of extents that are too long together.
Which versions are affected by CVE-2023-53506?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53506?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2023-53506 being exploited?
There is no known exploitation of CVE-2023-53506 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53506, DEBIAN-CVE-2023-53506, GHSA-wxmx-9x37-q992, UBUNTU-CVE-2023-53506.