CVE-2026-45919

What it is

In the Linux kernel, the following vulnerability has been resolved: sched/rt: Skip currently executing CPU in rto_next_cpu() CPU0 becomes overloaded when hosting a CPU-bound RT task, a non-CPU-bound RT task, and a CFS task stuck in kernel space. When other CPUs switch from RT to non-RT tasks, RT load balancing (LB) is triggered; with HAVE_RT_PUSH_IPI enabled, they send IPIs to CPU0 to drive the execution of rto_push_irq_work_func. During push_rt_task on CPU0, if next_task->prio < rq->donor->prio, resched_curr() sets NEED_RESCHED and after the push operation completes, CPU0 calls rto_next_cpu(). Since only CPU0 is overloaded in this scenario, rto_next_cpu() should ideally return -1 (no further IPI needed). However, multiple CPUs invoking tell_cpu_to_push() during LB increments rd->rto_loop_next. Even when rd->rto_cpu is set to -1, the mismatch between rd->rto_loop and rd->rto_loop_next forces rto_next_cpu() to restart its search from -1. With CPU0 remaining overloaded (satisfying rt_nr_migratory && rt_nr_total > 1), it gets reselected, causing CPU0 to queue irq_work to itself and send self-IPIs repeatedly. As long as CPU0 stays overloaded and other CPUs run pull_rt_tasks(), it falls into an infinite self-IPI loop, which triggers a CPU hardlockup due to continuous self-interrupts. The trigging scenario is as follows: cpu0 cpu1 cpu2 pull_rt_task tell_cpu_to_push <------------irq_work_queue_on rto_push_irq_work_func push_rt_task resched_curr(rq) pull_rt_task rto_next_cpu tell_cpu_to_push <-------------------------- atomic_inc(rto_loop_next) rd->rto_loop != next rto_next_cpu irq_work_queue_on rto_push_irq_work_func Fix redundant self-IPI by filtering the initiating CPU in rto_next_cpu(). This solution has been verified to effectively eliminate spurious self-IPIs and prevent CPU hardlockup scenarios.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-27 14:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-11-06 16:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-05-27 14:17 UTC

Last modified

2026-11-06 16:18 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-835

Record status

Undergoing Analysis

Affected

• Linux Kernel < 4.5
• Linux Kernel < 4.10
• Linux Kernel < 5.10.252
• Linux Kernel < 5.15.202
• Linux Kernel < 6.1.165
• Linux Kernel < 6.6.128
• Linux Kernel < 6.12.75
• Linux Kernel < 6.18.14

Attack profile CVSS 3.1 · 5.5

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-45919.md and follow it. Check whether this project is affected by CVE-2026-45919. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge