CVE-2026-4159: wolfSSL

Low severity, CVSS 3.3. EPSS: 0.1% chance of exploitation in the next 30 days.

1-byte OOB heap read in wc_PKCS7_DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wc_PKCS7_DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted content. Note that PKCS7 support is disabled by default.

Affected products

• wolfSSL wolfSSL: before 5.9.0 (fixed in 5.9.0)

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