{"id":"UBUNTU-CVE-2026-80225","details":"In NLnetLabs Unbound up to and including 1.26.0, a degradation of service vulnerability is present in the TCP/DoT reading procedure where there is no limit on consecutive reads. A malicious actor that can stream and sustain a rate of distinct uncached names over the TCP/DoT connection, monopolizes a single worker's entire event loop for as long as its writes stay ahead of the drain.","modified":"2026-11-11T09:58:14.422007026Z","published":"2026-09-16T09:17:00Z","related":["USN-8946-1","USN-8946-2"],"upstream":["CVE-2026-80225"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-80225"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-80225"},{"type":"REPORT","url":"https://nlnetlabs.nl/downloads/unbound/CVE-2026-80225.txt"},{"type":"REPORT","url":"https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-80225.txt"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8946-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8946-2"}],"affected":[{"package":{"name":"unbound","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/unbound?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.4-2ubuntu1.11+esm3"}]}],"versions":["1.9.0-2ubuntu1","1.9.0-2ubuntu2","1.9.4-2","1.9.4-2ubuntu1","1.9.4-2ubuntu1.1","1.9.4-2ubuntu1.2","1.9.4-2ubuntu1.3","1.9.4-2ubuntu1.4","1.9.4-2ubuntu1.5","1.9.4-2ubuntu1.6","1.9.4-2ubuntu1.8","1.9.4-2ubuntu1.9","1.9.4-2ubuntu1.11","1.9.4-2ubuntu1.11+esm1","1.9.4-2ubuntu1.11+esm2"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_version":"1.9.4-2ubuntu1.11+esm3","binary_name":"libunbound8"},{"binary_version":"1.9.4-2ubuntu1.11+esm3","binary_name":"python-unbound"},{"binary_name":"python3-unbound","binary_version":"1.9.4-2ubuntu1.11+esm3"},{"binary_name":"unbound","binary_version":"1.9.4-2ubuntu1.11+esm3"},{"binary_name":"unbound-anchor","binary_version":"1.9.4-2ubuntu1.11+esm3"},{"binary_name":"unbound-host","binary_version":"1.9.4-2ubuntu1.11+esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80225.json"}},{"package":{"name":"unbound","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/unbound?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.13.1-1ubuntu5.17"}]}],"versions":["1.13.1-1ubuntu1","1.13.1-1ubuntu3","1.13.1-1ubuntu5","1.13.1-1ubuntu5.1","1.13.1-1ubuntu5.2","1.13.1-1ubuntu5.3","1.13.1-1ubuntu5.4","1.13.1-1ubuntu5.5","1.13.1-1ubuntu5.7","1.13.1-1ubuntu5.8","1.13.1-1ubuntu5.10","1.13.1-1ubuntu5.11","1.13.1-1ubuntu5.12","1.13.1-1ubuntu5.13","1.13.1-1ubuntu5.14","1.13.1-1ubuntu5.15","1.13.1-1ubuntu5.16"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libunbound8","binary_version":"1.13.1-1ubuntu5.17"},{"binary_name":"python3-unbound","binary_version":"1.13.1-1ubuntu5.17"},{"binary_name":"unbound","binary_version":"1.13.1-1ubuntu5.17"},{"binary_version":"1.13.1-1ubuntu5.17","binary_name":"unbound-anchor"},{"binary_version":"1.13.1-1ubuntu5.17","binary_name":"unbound-host"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80225.json"}},{"package":{"name":"unbound","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/unbound?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.19.2-1ubuntu3.12"}]}],"versions":["1.17.1-2","1.18.0-2ubuntu1","1.18.0-2ubuntu2","1.19.1-1ubuntu1","1.19.2-1ubuntu1","1.19.2-1ubuntu3","1.19.2-1ubuntu3.1","1.19.2-1ubuntu3.2","1.19.2-1ubuntu3.3","1.19.2-1ubuntu3.4","1.19.2-1ubuntu3.5","1.19.2-1ubuntu3.6","1.19.2-1ubuntu3.7","1.19.2-1ubuntu3.8","1.19.2-1ubuntu3.9","1.19.2-1ubuntu3.10"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libunbound8","binary_version":"1.19.2-1ubuntu3.12"},{"binary_name":"python3-unbound","binary_version":"1.19.2-1ubuntu3.12"},{"binary_name":"unbound","binary_version":"1.19.2-1ubuntu3.12"},{"binary_version":"1.19.2-1ubuntu3.12","binary_name":"unbound-anchor"},{"binary_name":"unbound-host","binary_version":"1.19.2-1ubuntu3.12"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80225.json"}},{"package":{"name":"unbound","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/unbound?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.25.1-1ubuntu3.1"}]}],"versions":["1.24.2-1ubuntu2","1.25.1-1ubuntu1","1.25.1-1ubuntu3"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"1.25.1-1ubuntu3.1","binary_name":"libunbound8"},{"binary_name":"python3-unbound","binary_version":"1.25.1-1ubuntu3.1"},{"binary_name":"unbound","binary_version":"1.25.1-1ubuntu3.1"},{"binary_name":"unbound-anchor","binary_version":"1.25.1-1ubuntu3.1"},{"binary_version":"1.25.1-1ubuntu3.1","binary_name":"unbound-host"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80225.json"}},{"package":{"name":"unbound","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/unbound?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.24.2-1ubuntu2.4"}]}],"versions":["1.22.0-2ubuntu2","1.22.0-2ubuntu4","1.24.2-1ubuntu1","1.24.2-1ubuntu2","1.24.2-1ubuntu2.1","1.24.2-1ubuntu2.2","1.24.2-1ubuntu2.3"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"1.24.2-1ubuntu2.4","binary_name":"libunbound8"},{"binary_name":"python3-unbound","binary_version":"1.24.2-1ubuntu2.4"},{"binary_name":"unbound","binary_version":"1.24.2-1ubuntu2.4"},{"binary_name":"unbound-anchor","binary_version":"1.24.2-1ubuntu2.4"},{"binary_version":"1.24.2-1ubuntu2.4","binary_name":"unbound-host"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80225.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}