Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net 0.26.0-alpha.1 before 0.26.2 contain a DNSSEC validation flaw in DnssecDnsHandle that accepts NSEC3-signed NODATA responses for zone-apex queries as secure without an NSEC3 record matching the hashed QNAME. On-path attackers or malicious authoritative servers can replay a validly signed non-apex NSEC3 with the zone's signed SOA to serve an authenticated (AD=1) denial of any apex RRtype for the negative-cache TTL.