NLnet Labs Unbound up to and including version 1.26.1 contains multiple vulnerabilities including a cache-level side-channel that can be exploited under specific non-default configurations, DNSSEC validation bypasses in certain trust-anchor configurations, and a denial-of-service condition via excessive compression pointer traversal. These issues can lead to cache poisoning, incorrect DNSSEC validation resulting in insecure treatment of zones, and performance degradation. A fix is available in version 1.17.1-25.oe2403sp3.