CVE-2026-31574 clockevents: Add missing resets of the next_event_forced flag
A missing flag reset in the Linux kernel clockevents subsystem can cause timer interrupt starvation, leading to system stalls and denial of service.
- 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-2026-31574?
CVE-2026-31574 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:
clockevents: Add missing resets of the next_event_forced flag
The prevention mechanism against timer interrupt starvation missed to reset the next_event_forced flag in a couple of places:
- When the clock event state changes. That can cause the flag to be stale over a shutdown/startup sequence
- When a non-forced event is armed, which then prevents rearming before that event. If that event is far out in the future this will cause missed timer interrupts.
- In the suspend wakeup handler.
That led to stalls which have been reported by several people.
Add the missing resets, which fixes the problems for the reporters.
Which versions are affected by CVE-2026-31574?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31574?
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-2026-31574 being exploited?
There is no known exploitation of CVE-2026-31574 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as GHSA-w5vp-hvm6-339g, ROOT-OS-DEBIAN-11-CVE-2026-31574, ROOT-OS-DEBIAN-12-CVE-2026-31574, ROOT-OS-DEBIAN-13-CVE-2026-31574, UBUNTU-CVE-2026-31574.