CVE-2021-41581: OpenBSD Libressl

Medium severity, CVSS 5.5. EPSS: 0.6% chance of exploitation in the next 30 days.

x509_constraints_parse_mailbox in lib/libcrypto/x509/x509_constraints.c in LibreSSL through 3.4.0 has a stack-based buffer over-read. When the input exceeds DOMAIN_PART_MAX_LEN, the buffer lacks '\0' termination.

Affected products

• OpenBSD Libressl: up to and including 3.4.0

Published 2021-09-24. Last modified 2026-06-17.