CVE-2025-52496: Arm Mbed TLS

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler optimizations occur. An attacker may be able to extract an AES key from a multithreaded program, or perform a GCM forgery.

Affected products

• Arm Mbed TLS: before 3.6.4 (fixed in 3.6.4)

Published 2025-07-04. Last modified 2026-06-17.