CVE-2026-2646: wolfSSL

High severity, CVSS 8.1. EPSS: 0.2% chance of exploitation in the next 30 days.

A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSL_d2i_SSL_SESSION() function. When deserializing session data with SESSION_CERTS enabled, certificate and session id lengths are read from an untrusted input without bounds validation, allowing an attacker to overflow fixed-size buffers and corrupt heap memory. A maliciously crafted session would need to be loaded from an external source to trigger this vulnerability. Internal sessions were not vulnerable.

Affected products

• wolfSSL wolfSSL: before 5.9.0 (fixed in 5.9.0)

Published 2026-03-19. Last modified 2026-06-17.