{"id":"CVE-2023-26249","details":"Knot Resolver before 5.6.0 enables attackers to consume its resources, launching amplification attacks and potentially causing a denial of service. Specifically, a single client query may lead to a hundred TCP connection attempts if a DNS server closes connections without providing a response.","modified":"2026-08-12T03:51:13.180599849Z","published":"2023-02-21T00:00:00Z","database_specific":{"cna_assigner":"mitre","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/26xxx/CVE-2023-26249.json","unresolved_ranges":[{"source":"DESCRIPTION","extracted_events":[{"fixed":"5.6.0"}]}]},"references":[{"type":"WEB","url":"https://www.knot-resolver.cz/2023-01-26-knot-resolver-5.6.0.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/26xxx/CVE-2023-26249.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-26249"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/cz-nic/knot-resolver","events":[{"introduced":"0"},{"fixed":"2425110cb28ce3c3f6a21f5935188a272b4479ed"}],"database_specific":{"cpe":"cpe:2.3:a:nic:knot_resolver:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"5.6.0"}],"source":"CPE_RANGE"}}],"versions":["v5.5.3","v5.3.1","v5.5.2","v5.5.1","v5.5.0","v5.3.2","v5.4.3","v5.4.2","v5.4.1","v5.4.0","v5.3.0","v5.2.1","v5.2.0","v5.1.3","v5.1.2","v5.1.1","v5.1.0","v5.0.1","v5.0.0","v4.3.0","v4.2.2","v4.2.0","v4.1.0","v4.0.0","v3.2.1","v3.2.0","v3.1.0","v3.0.0","v2.4.0","v2.3.0","v2.2.0","v2.1.1","v2.1.0","v2.0.0","v1.5.1","v1.5.0","v1.4.0","v1.3.3","v1.3.2","v1.3.1","v1.3.0","v1.2.6","v1.2.1","v1.2.0","v1.2.0-rc3","v1.2.0-rc2","v1.2.0-rc1","v1.1.1","v1.1.0","v1.0.0","v1.0.0-beta3","v1.0.0-beta2","v1.0.0-beta1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-26249.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"}]}