CVE-2025-52497: Arm Mbed TLS

Medium severity, CVSS 4.8. EPSS: 0.3% chance of exploitation in the next 30 days.

Mbed TLS before 3.6.4 has a PEM parsing one-byte heap-based buffer underflow, in mbedtls_pem_read_buffer and two mbedtls_pk_parse functions, via untrusted PEM input.

Affected products

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

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