CVE-2023-53861 ext4: correct grp validation in ext4_mb_good_group
A null pointer dereference in the Linux kernel ext4 filesystem allows local attackers to cause a system crash via corrupted group data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-53861?
CVE-2023-53861 is a vulnerability in Linux, published on 9 Dec 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:
ext4: correct grp validation in ext4_mb_good_group
Group corruption check will access memory of grp and will trigger kernel crash if grp is NULL. So do NULL check before corruption check.
Which versions are affected by CVE-2023-53861?
How do I fix CVE-2023-53861?
Apply the vendor's patch.
Is CVE-2023-53861 being exploited?
There is no known exploitation of CVE-2023-53861 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-53861, DEBIAN-CVE-2023-53861, GHSA-9chw-7w35-c7qm, UBUNTU-CVE-2023-53861.