CVE-2026-34871: Arm Mbed TLS

Medium severity, CVSS 6.7. EPSS: 0.2% chance of exploitation in the next 30 days.

An issue was discovered in Mbed TLS before 3.6.6 and 4.x before 4.1.0 and TF-PSA-Crypto before 1.1.0. There is a Predictable Seed in a Pseudo-Random Number Generator (PRNG).

Affected products

• Arm Mbed TLS: before 3.6.6 (fixed in 3.6.6)
• Trustedfirmware Tf-Psa-Crypto: before 1.1.0 (fixed in 1.1.0)

Published 2026-04-01. Last modified 2026-06-17.