System call entry on Cortex M (and possibly R and A, but I think not) has a race which allows very practical privilege escalation for malicious userspace processes.
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3r6j-5mp3-75wr
Source: Mitre, NVD
Published: 2025-11-11
Updated: 2025-11-12
Base Score: 6.2
Vector: CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C
Severity: Medium
Base Score: 8.1
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Severity: High
EPSS: 0.00013