CVE-2026-5500: wolfSSL

Medium severity, CVSS 5.9. EPSS: 0.4% chance of exploitation in the next 30 days.

wolfSSL's wc_PKCS7_DecodeAuthEnvelopedData() does not properly sanitize the AES-GCM authentication tag length received and has no lower bounds check. A man-in-the-middle can therefore truncate the mac field from 16 bytes to 1 byte, reducing the tag check from 2⁻¹²⁸ to 2⁻⁸.

Affected products

• wolfSSL wolfSSL: up to and including 5.9.0

Published 2026-04-10. Last modified 2026-06-17.