{"id":"UBUNTU-CVE-2026-11605","details":"The issue is a resource exhaustion vulnerability associated with DNSSEC validation. BIND always validates all RRSIG records in an answer, even if they are not strictly needed. A query to an authoritative server/zone which returns many valid but superfluous RRSIG records causes the validator to waste disproportionate CPU time. This issue affects BIND 9 versions 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and 9.20.9-S1 through 9.20.24-S1.","modified":"2026-08-19T18:51:23.131080387Z","published":"2026-07-22T15:16:00Z","related":["USN-8648-1"],"upstream":["CVE-2026-11605"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-11605"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-11605"},{"type":"REPORT","url":"https://kb.isc.org/docs/cve-2026-11605"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8648-1"}],"affected":[{"package":{"name":"bind9","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/bind9?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.20.24-1ubuntu0.2"}]}],"versions":["1:9.20.11-1ubuntu2","1:9.20.11-1ubuntu3","1:9.20.18-1ubuntu1","1:9.20.18-1ubuntu2","1:9.20.18-1ubuntu2.1","1:9.20.24-1ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"bind9","binary_version":"1:9.20.24-1ubuntu0.2"},{"binary_name":"bind9-dnsutils","binary_version":"1:9.20.24-1ubuntu0.2"},{"binary_name":"bind9-host","binary_version":"1:9.20.24-1ubuntu0.2"},{"binary_name":"bind9-libs","binary_version":"1:9.20.24-1ubuntu0.2"},{"binary_name":"bind9-utils","binary_version":"1:9.20.24-1ubuntu0.2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-11605.json"}}],"schema_version":"1.9.0","severity":[{"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"}]}