CVE-2026-43820

NIOSSLCertificate.subjectAlternativeNames provides access to the raw bytes for a cert's SANs. NIOSSL provides access to a buffer assumed to be backed by an ASN1STRING, but not all SANs are backed by ASN1STRING, so accessing the buffer for such a type can lead to out-of-bounds memory access. This...

CVE-2026-43820

The CVE-2026-43820 vulnerability affects the NIOSSL component used with SwiftNIO SSL. NIOSSLCertificate._subjectAlternativeNames exposes the raw bytes of a certificate’s SANs; NIOSSL may expose a buffer expected to be backed by an ASN1_STRING, but not all SAN types are backed accordingly, which c...