CVE-2026-44621

Descrição

With NLnet Labs Unbound up to and including version 1.25.1, applications using libunbound and configured with -unwanted-reply-threshold-, could eventually be abruptly terminated if the threshold is reached and libunbound needs to call -libworker_alloc_cleanup- since the function is absent from the function call allow list. When an application using libunbound sets -unwanted-reply-threshold- to any non-zero value and the iterator queries an authoritative that replies with enough wrong-transaction-ID UDP datagrams to cross the threshold, the -libworker_alloc_cleanup- will eventually be called. Since the function is absent from the function call allow list, this leads to a fatal exit of libunbound and eventual termination of the embedding application.Unbound itself is not affected since its relevant function -worker_alloc_cleanup- is registed in the allow list and proceeds to perform the documented cache flush.