CVE-2026-5263: wolfSSL

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

URI nameConstraints from constrained intermediate CAs are parsed but not enforced during certificate chain verification in wolfcrypt/src/asn.c. A compromised or malicious sub-CA could issue leaf certificates with URI SAN entries that violate the nameConstraints of the issuing CA, and wolfSSL would accept them as valid.

Affected products

• wolfSSL wolfSSL: before 5.9.1 (fixed in 5.9.1)

Published 2026-04-09. Last modified 2026-07-02.