CVE-2026-23298 can: ucan: Fix infinite loop from zero-length messages
A malicious or broken USB CAN device can cause a system hang via an infinite loop in the ucan driver, requiring a kernel patch.
- 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-2026-23298?
CVE-2026-23298 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Mar 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:
can: ucan: Fix infinite loop from zero-length messages
If a broken ucan device gets a message with the message length field set to 0, then the driver will loop for forever in ucan_read_bulk_callback(), hanging the system. If the length is 0, just skip the message and go on to the next one.
This has been fixed in the kvaser_usb driver in the past in commit 0c73772cd2b8 ("can: kvaser_usb: leaf: Fix potential infinite loop in command parsers"), so there must be some broken devices out there like this somewhere.
Weakness: CWE-835
Which versions are affected by CVE-2026-23298?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23298?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-23298 being exploited?
There is no known exploitation of CVE-2026-23298 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-80658, BELL-CVE-2026-23298, DEBIAN-CVE-2026-23298, GHSA-v7rc-q48q-f2p3, ROOT-OS-DEBIAN-11-CVE-2026-23298, ROOT-OS-DEBIAN-12-CVE-2026-23298 and 4 more.