Couchbase Server 6.5.x and 6.6.x through 6.6.2 has Incorrect Access Control. Externally managed users are not prevented from using an empty password, per RFC4513.
Couchbase Server 6.5.x, 6.6.x through 6.6.2, and 7.0.0 has a Buffer Overflow. A specially crafted network packet sent from an attacker can crash memcached.
Couchbase Server 6.5.x, 6.6.0 through 6.6.2, and 7.0.0, has a Buffer Overflow. A specially crafted network packet sent from an attacker can crash memcached.