CVE-2025-21965: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl() If a BPF scheduler provides an invalid CPU (outside the nr_cpu_ids range) as prev_cpu to scx_bpf_select_cpu_dfl() it can cause a kernel crash. To prevent this, validate prev_cpu in scx_bpf_select_cpu_dfl() and trigger an scx error if an invalid CPU is specified.

Affected products

• Linux Linux Kernel: from 6.12, before 6.12.20 (fixed in 6.12.20); from 6.13, before 6.13.8 (fixed in 6.13.8); version 6.14 only

Published 2025-04-01. Last modified 2026-07-30.