CVE-2026-89136: wolfSSL

High severity, CVSS 8.3. EPSS: 0.6% chance of exploitation in the next 30 days.

When using RPK (Raw Public Key), the client side of a TLS 1.2, 1.3 and DTLS 1.2 connection could accept an unsolicited server_cert_type=RawPublicKey which allowed a malicious or misbehaving server to bypass authentication. RPK is off by default and only enabled in --enable-rpk OR --enable-all OR --enable-distro AKA HAVE_RPK builds.

Affected products

• wolfSSL wolfSSL: from 5.6.0, up to and including 5.9.2

Published 2026-09-27. Last modified 2026-09-29.