CVE-2025-68799 caif: fix integer underflow in cffrml_receive()
An attacker can cause kernel instability and potential information disclosure via integer underflow in the CAIF protocol when FCS is disabled.
- 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-2025-68799?
CVE-2025-68799 is a high-severity 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:
caif: fix integer underflow in cffrml_receive()
The cffrml_receive() function extracts a length field from the packet header and, when FCS is disabled, subtracts 2 from this length without validating that len >= 2.
If an attacker sends a malicious packet with a length field of 0 or 1 to an interface with FCS disabled, the subtraction causes an integer underflow.
This can lead to memory exhaustion and kernel instability, potential information disclosure if padding contains uninitialized kernel memory.
Fix this by validating that len >= 2 before performing the subtraction.
Which versions are affected by CVE-2025-68799?
How do I fix CVE-2025-68799?
Apply the vendor's patch.
Is CVE-2025-68799 being exploited?
There is no known exploitation of CVE-2025-68799 in the wild and no public exploit code.
Sources
Also known as AZL-74327, BELL-CVE-2025-68799, DEBIAN-CVE-2025-68799, GHSA-pxpq-p89v-xx8g, ROOT-OS-DEBIAN-11-CVE-2025-68799, ROOT-OS-DEBIAN-12-CVE-2025-68799 and 4 more.