{"id":"USN-8951-1","summary":"c-ares vulnerabilities","details":"It was discovered that c-ares incorrectly parsed certain SOA replies. A\nremote attacker could possibly use this issue to cause c-ares to crash,\nresulting in a denial of service. This issue only affected Ubuntu 16.04 LTS\nand Ubuntu 18.04 LTS. (CVE-2020-22217)\n\nIt was discovered that c-ares incorrectly handled certain sortlist strings.\nA remote attacker could possibly use this issue to cause c-ares to crash,\nresulting in a denial of service, or execute arbitrary code. This issue\nonly affected Ubuntu 16.04 LTS. (CVE-2022-4904)\n\nIt was discovered that c-ares did not properly limit DNS compression\npointer hops or assembled name lengths when parsing DNS names. A remote\nattacker could possibly use this issue to cause c-ares to use excessive\nresources, resulting in a denial of service. (CVE-2026-69184)\n\nIt was discovered that c-ares did not properly validate record count fields\nbefore allocating memory when parsing DNS responses. A remote attacker\ncould possibly use this issue to cause c-ares to use excessive resources,\nresulting in a denial of service. This issue only affected Ubuntu 24.04 LTS\nand Ubuntu 26.04 LTS. (CVE-2026-69186)","modified":"2026-10-22T04:42:58.035678055Z","published":"2026-10-21T18:20:42Z","related":["UBUNTU-CVE-2020-22217","UBUNTU-CVE-2022-4904","UBUNTU-CVE-2026-69184","UBUNTU-CVE-2026-69186"],"upstream":["CVE-2020-22217","CVE-2022-4904","CVE-2026-69184","CVE-2026-69186","UBUNTU-CVE-2020-22217","UBUNTU-CVE-2022-4904","UBUNTU-CVE-2026-69184","UBUNTU-CVE-2026-69186"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8951-1"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-22217"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2022-4904"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-69184"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-69186"}],"affected":[{"package":{"name":"c-ares","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/c-ares?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.10.0-3ubuntu0.2+esm4"}]}],"versions":["1.10.0-2","1.10.0-3","1.10.0-3ubuntu0.1","1.10.0-3ubuntu0.2","1.10.0-3ubuntu0.2+esm1","1.10.0-3ubuntu0.2+esm2","1.10.0-3ubuntu0.2+esm3"],"ecosystem_specific":{"binaries":[{"binary_version":"1.10.0-3ubuntu0.2+esm4","binary_name":"libc-ares2"}],"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:16.04:LTS","cves":[{"id":"CVE-2020-22217","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"}]},{"id":"CVE-2022-4904","severity":[{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H","type":"CVSS_V3"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H"},{"type":"Ubuntu","score":"medium"}]},{"id":"CVE-2026-69184","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"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8951-1.json"}},{"package":{"name":"c-ares","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/c-ares?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.14.0-1ubuntu0.2+esm3"}]}],"versions":["1.13.0-2","1.13.0-3","1.14.0-1","1.14.0-1ubuntu0.1","1.14.0-1ubuntu0.2","1.14.0-1ubuntu0.2+esm1","1.14.0-1ubuntu0.2+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"libc-ares2","binary_version":"1.14.0-1ubuntu0.2+esm3"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:18.04:LTS","cves":[{"severity":[{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"type":"Ubuntu","score":"medium"}],"id":"CVE-2020-22217"},{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"score":"medium","type":"Ubuntu"}],"id":"CVE-2026-69184"}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8951-1.json"}},{"package":{"name":"c-ares","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/c-ares?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.15.0-1ubuntu0.5+esm1"}]}],"versions":["1.15.0-1build1","1.15.0-1ubuntu0.1","1.15.0-1ubuntu0.2","1.15.0-1ubuntu0.3","1.15.0-1ubuntu0.4","1.15.0-1ubuntu0.5"],"ecosystem_specific":{"binaries":[{"binary_name":"libc-ares2","binary_version":"1.15.0-1ubuntu0.5+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:20.04:LTS","cves":[{"id":"CVE-2026-69184","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"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8951-1.json"}},{"package":{"name":"c-ares","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/c-ares?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.18.1-1ubuntu0.22.04.4"}]}],"versions":["1.17.1-1ubuntu1","1.18.1-1","1.18.1-1build1","1.18.1-1ubuntu0.22.04.1","1.18.1-1ubuntu0.22.04.2","1.18.1-1ubuntu0.22.04.3"],"ecosystem_specific":{"binaries":[{"binary_name":"libc-ares2","binary_version":"1.18.1-1ubuntu0.22.04.4"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8951-1.json","cves_map":{"cves":[{"id":"CVE-2026-69184","severity":[{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]}],"ecosystem":"Ubuntu:22.04:LTS"}}},{"package":{"name":"c-ares","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/c-ares?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.27.0-1.0ubuntu1.1"}]}],"versions":["1.19.1-3","1.20.1-1","1.26.0-1","1.27.0-1","1.27.0-1.0ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.27.0-1.0ubuntu1.1","binary_name":"libcares2"}],"availability":"No subscription required"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:24.04:LTS","cves":[{"id":"CVE-2026-69184","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"}]},{"id":"CVE-2026-69186","severity":[{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","type":"CVSS_V3"},{"type":"Ubuntu","score":"medium"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8951-1.json"}},{"package":{"name":"c-ares","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/c-ares?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.34.6-1ubuntu0.2"}]}],"versions":["1.34.5-1","1.34.6-1","1.34.6-1ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libc-ares2","binary_version":"1.34.6-1ubuntu0.2"},{"binary_version":"1.34.6-1ubuntu0.2","binary_name":"libcares2"}],"availability":"No subscription required"},"database_specific":{"cves_map":{"cves":[{"id":"CVE-2026-69184","severity":[{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","type":"CVSS_V3"},{"type":"Ubuntu","score":"medium"}]},{"id":"CVE-2026-69186","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":"Ubuntu","score":"medium"}]}],"ecosystem":"Ubuntu:26.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8951-1.json"}}],"schema_version":"1.9.0"}