{"id":"UBUNTU-CVE-2026-33261","details":"A zone transition from NSEC to NSEC3 might trigger an internal inconsistency and cause a denial of service.","modified":"2026-05-20T16:25:28.589786585Z","published":"2026-04-22T10:16:00Z","upstream":["CVE-2026-33261"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-33261"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-33261"},{"type":"REPORT","url":"https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2026-03.html#cve-2026-33261-null-pointer-access-in-aggressive-nsec-3-cache"}],"affected":[{"package":{"name":"pdns-recursor","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/pdns-recursor?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.7.3-1","4.0.0~alpha1-1","4.0.0~alpha1-2","4.0.0~alpha2-2","4.0.0~alpha2-2ubuntu0.1","4.0.0~alpha2-2ubuntu0.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"pdns-recursor","binary_version":"4.0.0~alpha2-2ubuntu0.1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33261.json"}},{"package":{"name":"pdns-recursor","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/pdns-recursor?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.6-1","4.0.6-1build1","4.0.7-1","4.1.1-1","4.1.1-1build1","4.1.1-2","4.1.1-2ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"pdns-recursor","binary_version":"4.1.1-2ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33261.json"}},{"package":{"name":"pdns-recursor","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/pdns-recursor?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.0-6","4.2.1-1","4.2.1-1build1","4.2.1-1build2","4.2.1-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"4.2.1-1ubuntu0.1~esm1","binary_name":"pdns-recursor"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33261.json"}},{"package":{"name":"pdns-recursor","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/pdns-recursor?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.2-3","4.6.0-1ubuntu1","4.6.0-1ubuntu1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"pdns-recursor","binary_version":"4.6.0-1ubuntu1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33261.json"}},{"package":{"name":"pdns-recursor","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/pdns-recursor?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.9.0-2","4.9.1-4","4.9.2-1","4.9.2-1build1","4.9.2-2","4.9.3-1","4.9.3-1build2","4.9.3-1build3"],"ecosystem_specific":{"binaries":[{"binary_name":"pdns-recursor","binary_version":"4.9.3-1build3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33261.json"}},{"package":{"name":"pdns-recursor","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/pdns-recursor?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.0-5","5.2.2-1","5.2.2-2","5.2.4-2","5.2.4-2build2"],"ecosystem_specific":{"binaries":[{"binary_version":"5.2.4-2build2","binary_name":"pdns-recursor"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33261.json"}},{"package":{"name":"pdns-recursor","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/pdns-recursor?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.4-2build2","5.3.1-1","5.3.3-1","5.3.4-1","5.3.4-1build1","5.3.4-2","5.3.5-1"],"ecosystem_specific":{"binaries":[{"binary_name":"pdns-recursor","binary_version":"5.3.5-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33261.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"},{"type":"Ubuntu","score":"medium"}]}