CVE-2025-40020 can: peak_usb: fix shift-out-of-bounds issue
A shift-out-of-bounds error in the Linux kernel peak_usb CAN driver can cause a denial of service.
- 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-2025-40020?
CVE-2025-40020 is a vulnerability in Linux, published on 24 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:
can: peak_usb: fix shift-out-of-bounds issue
Explicitly uses a 64-bit constant when the number of bits used for its shifting is 32 (which is the case for PC CAN FD interfaces supported by this driver).
[mkl: update subject, apply manually]
Which versions are affected by CVE-2025-40020?
How do I fix CVE-2025-40020?
Apply the vendor's patch.
Is CVE-2025-40020 being exploited?
There is no known exploitation of CVE-2025-40020 in the wild and no public exploit code.
Sources
Also known as AZL-68808, BELL-CVE-2025-40020, DEBIAN-CVE-2025-40020, GHSA-577q-2j8x-rg25, ROOT-OS-DEBIAN-11-CVE-2025-40020, ROOT-OS-DEBIAN-12-CVE-2025-40020 and 3 more.