CVE-2020-36423: Arm Mbed TLS

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.

Affected products

• Arm Mbed TLS: before 2.16.7 (fixed in 2.16.7); from 2.17.0, before 2.23.0 (fixed in 2.23.0)
• Debian Debian Linux: version 10.0 only

Published 2021-07-19. Last modified 2026-06-17.