CVE-2026-31605 fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO
A divide-by-zero error in the udlfb driver allows local attackers to crash the system via FBIOPUT_VSCREENINFO ioctl calls.
- 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-2026-31605?
CVE-2026-31605 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 Apr 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:
fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO
Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide by zero error"), we also need to prevent that same crash from happening in the udlfb driver as it uses pixclock directly when dividing, which will crash.
Weakness: CWE-369
Which versions are affected by CVE-2026-31605?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31605?
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-2026-31605 being exploited?
There is no known exploitation of CVE-2026-31605 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-83687, BELL-CVE-2026-31605, DEBIAN-CVE-2026-31605, GHSA-5j7x-34ch-2fxf, ROOT-OS-DEBIAN-11-CVE-2026-31605, ROOT-OS-DEBIAN-12-CVE-2026-31605 and 3 more.