CVE-2021-27562: Arm Trusted Firmware Out-of-Bounds Write Vulnerability

Medium severity, CVSS 5.5. Actively exploited: in CISA KEV since 2021-11-03. EPSS: 3.1% chance of exploitation in the next 30 days.

In Arm Trusted Firmware M through 1.2, the NS world may trigger a system halt, an overwrite of secure data, or the printing out of secure data when calling secure functions under the NSPE handler mode.

Affected products

• Trustedfirmware Trusted Firmware-M: up to and including 1.2.0

Published 2021-05-25. Last modified 2026-06-17.