CVE-2025-68797 char: applicom: fix NULL pointer dereference in ac_ioctl
A local attacker can cause a denial of service via a NULL pointer dereference in the applicom character driver when using a specific ioctl command.
- 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-2025-68797?
CVE-2025-68797 is a vulnerability in Linux, published on 13 Jan 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:
char: applicom: fix NULL pointer dereference in ac_ioctl
Discovered by Atuin - Automated Vulnerability Discovery Engine.
In ac_ioctl, the validation of IndexCard and the check for a valid RamIO pointer are skipped when cmd is 6. However, the function unconditionally executes readb(apbs[IndexCard].RamIO + VERS) at the end.
If cmd is 6, IndexCard may reference a board that does not exist (where RamIO is NULL), leading to a NULL pointer dereference.
Fix this by skipping the readb access when cmd is 6, as this command is a global information query and does not target a specific board context.
Which versions are affected by CVE-2025-68797?
How do I fix CVE-2025-68797?
Apply the vendor's patch.
Is CVE-2025-68797 being exploited?
There is no known exploitation of CVE-2025-68797 in the wild and no public exploit code.
Sources
Also known as AZL-74459, BELL-CVE-2025-68797, DEBIAN-CVE-2025-68797, GHSA-rm79-9rvw-rjv2, ROOT-OS-DEBIAN-11-CVE-2025-68797, ROOT-OS-DEBIAN-12-CVE-2025-68797 and 4 more.