{"id":"CVE-2026-44621","details":"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.","modified":"2026-08-12T18:48:02.622730532Z","published":"2026-07-22T14:17:18.913Z","related":["SUSE-SU-2026:23050-1","openSUSE-SU-2026:11380-1","openSUSE-SU-2026:21550-1"],"references":[{"type":"ADVISORY","url":"https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-44621.txt"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nlnetlabs/unbound","events":[{"introduced":"0"},{"fixed":"c33ad1b1a21e48bfe4f140e90252a9be1b0c5745"}],"database_specific":{"cpe":"cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"1.25.2"}],"source":"CPE_RANGE"}}],"versions":["release-1.25.1","release-1.25.0","release-1.25.0rc1","release-1.24.0","release-1.24.0rc1","release-1.23.0rc1","release-1.22.0","release-1.22.0rc1","release-1.21.0","release-1.21.0rc1","release-1.20.0rc1","release-1.20.0","release-1.19.3rc1","release-1.19.0rc1","release-1.19.0","release-1.18.0","release-1.18.0rc1","release-1.16.2","release-1.16.1rc1","release-1.16.1","release-1.16.0rc1","release-1.16.0","release-1.15.0rc1","release-1.15.0","release-1.14.0rc1","release-1.14.0","release-1.13.2","release-1.13.2rc1","release-1.13.1rc2","release-1.13.1","release-1.13.1rc1","release-1.13.0rc4","release-1.13.0rc3","release-1.13.0rc2","release-1.13.0rc1","release-1.12.0rc1","release-1.12.0","release-1.11.0rc1","release-1.11.0","1.11.0rc1","release-1.10.0rc2","release-1.10.0rc1","release-1.9.6","release-1.9.6rc1","release-1.9.3rc2","release-1.9.3","release-1.9.3rc1","release-1.9.2","release-1.9.2rc3","release-1.9.2rc1","release-1.9.2rc2","final-svn-state","release-1.9.1rc1","release-1.9.0rc1","release-1.8.2rc1","release-1.8.1rc1","release-1.8.0rc1","release-1.7.3rc1","release-1.7.2rc1","release-1.7.1rc1","release-1.7.0rc3","release-1.7.0rc2","release-1.7.0rc1","release-1.6.7","release-1.6.7rc1","release-1.6.6rc2","release-1.6.6rc1","release-1.6.4rc2","release-1.6.4rc1","release-1.6.2rc1","release-1.6.1rc3","release-1.6.1rc2","release-1.6.1rc1","release-1.6.0rc1","release-1.5.10rc1","release-1.5.10","release-1.5.9rc1","release-1.5.8rc1","release-1.5.8","release-1.5.7","release-1.5.6","release-1.5.6rc1","release-1.5.5","release-1.5.5rc1","release-1.5.4rc1","release-1.5.4","release-1.5.3rc1","release-1.5.2","release-1.5.2rc1","release-1.5.1","release-1.5.1rc2","release-1.5.1rc1","release-1.5.0rc1","release-1.4.22","release-1.4.22rc1","release-1.4.20","release-1.4.19","release-1.4.19rc1","release-1.4.18rc2","release-1.4.18rc1","release-1.4.17","release-1.4.17rc1","release-1.4.14","release-1.4.14rc1","release-1.4.13","release-1.4.13rc2","release-1.4.13rc1","release-1.4.12rc1","release-1.4.11rc3","release-1.4.11","release-1.4.11rc2","release-1.4.11rc1","release-1.4.9","release-1.4.9rc1","release-1.4.8rc1","release-1.4.7","release-1.4.7rc1","release-1.4.6","release-1.4.6rc1","release-1.4.5","release-1.4.5rc1","release-1.4.4","release-1.4.4rc1","release-1.4.3","release-1.4.2","release-1.4.1","release-1.4.0","release-1.4.0rc1","release-1.3.3","release-1.3.3rc1","release-1.3.2","release-1.3.1","release-1.1.1","release-1.0.1","release-0.11","release-0.10","release-0.8","release-0.7","release-0.6","release-0.5","release-0.4","release-0.3","release-0.1","release-0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44621.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}