CVE-2025-5866: Rt-Thread

Critical severity, CVSS 9.8. EPSS: 0.9% chance of exploitation in the next 30 days.

A vulnerability classified as critical has been found in RT-Thread 5.1.0. This affects the function sys_sigprocmask of the file rt-thread/components/lwp/lwp_syscall.c. The manipulation of the argument how leads to improper validation of array index.

Affected products

• Rt-Thread Rt-Thread: version 5.1.0 only

Published 2025-06-09. Last modified 2026-06-17.