{"id":"UBUNTU-CVE-2026-121506","details":"An out-of-bounds read and write in NTS client extension field parsing (extens_client_recv) in NTPsec before 1.2.5 allows a remote attacker who can send NTP server-mode replies to an NTS client to corrupt heap memory and crash ntpd, and, combined with the NTS-KE client out-of-bounds read fixed in 1.2.4, to bypass NTS authentication and set the client's time, via an NTS Authenticator and Encrypted Extension Fields field whose nonce length exceeds the field.","modified":"2026-11-05T11:46:31.486340939Z","published":"2026-11-03T15:17:00Z","upstream":["CVE-2026-121506"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-121506"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-121506"},{"type":"REPORT","url":"https://gitlab.com/NTPsec/ntpsec/-/commit/0a36941e499d533dfbc3fb6b1fcd8c367679d719"},{"type":"REPORT","url":"https://gitlab.com/NTPsec/ntpsec/-/work_items/902"}],"affected":[{"package":{"name":"ntpsec","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/ntpsec?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.0+dfsg1-1","1.0.0+dfsg1-3","1.1.0+dfsg1-1","1.1.0+dfsg1-1ubuntu0.1","1.1.0+dfsg1-1ubuntu0.2"],"ecosystem_specific":{"binaries":[{"binary_name":"ntpsec","binary_version":"1.1.0+dfsg1-1ubuntu0.2"},{"binary_version":"1.1.0+dfsg1-1ubuntu0.2","binary_name":"ntpsec-ntpdate"},{"binary_version":"1.1.0+dfsg1-1ubuntu0.2","binary_name":"ntpsec-ntpviz"},{"binary_name":"python3-ntp","binary_version":"1.1.0+dfsg1-1ubuntu0.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121506.json"}},{"package":{"name":"ntpsec","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/ntpsec?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.3+dfsg1-2","1.1.7+dfsg1-1","1.1.7+dfsg1-2","1.1.8+dfsg1-1","1.1.8+dfsg1-3","1.1.8+dfsg1-4","1.1.8+dfsg1-4build1"],"ecosystem_specific":{"binaries":[{"binary_name":"ntpsec","binary_version":"1.1.8+dfsg1-4build1"},{"binary_version":"1.1.8+dfsg1-4build1","binary_name":"ntpsec-ntpdate"},{"binary_name":"ntpsec-ntpviz","binary_version":"1.1.8+dfsg1-4build1"},{"binary_name":"python3-ntp","binary_version":"1.1.8+dfsg1-4build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121506.json"}},{"package":{"name":"ntpsec","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/ntpsec?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.0+dfsg1-4","1.2.1+dfsg1-2","1.2.1+dfsg1-3","1.2.1+dfsg1-3ubuntu1","1.2.1+dfsg1-4"],"ecosystem_specific":{"binaries":[{"binary_name":"ntpsec","binary_version":"1.2.1+dfsg1-4"},{"binary_name":"ntpsec-ntpdate","binary_version":"1.2.1+dfsg1-4"},{"binary_name":"ntpsec-ntpviz","binary_version":"1.2.1+dfsg1-4"},{"binary_name":"python3-ntp","binary_version":"1.2.1+dfsg1-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121506.json"}},{"package":{"name":"ntpsec","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/ntpsec?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.2+dfsg1-2","1.2.2+dfsg1-3","1.2.2+dfsg1-4","1.2.2+dfsg1-4build1","1.2.2+dfsg1-4build2"],"ecosystem_specific":{"binaries":[{"binary_name":"ntp","binary_version":"1:4.2.8p15+dfsg-2~1.2.2+dfsg1-4build2"},{"binary_name":"ntpdate","binary_version":"1:4.2.8p15+dfsg-2~1.2.2+dfsg1-4build2"},{"binary_version":"1.2.2+dfsg1-4build2","binary_name":"ntpsec"},{"binary_version":"1.2.2+dfsg1-4build2","binary_name":"ntpsec-ntpdate"},{"binary_name":"ntpsec-ntpdig","binary_version":"1.2.2+dfsg1-4build2"},{"binary_name":"ntpsec-ntpviz","binary_version":"1.2.2+dfsg1-4build2"},{"binary_version":"1.2.2+dfsg1-4build2","binary_name":"python3-ntp"},{"binary_name":"sntp","binary_version":"1:4.2.8p15+dfsg-2~1.2.2+dfsg1-4build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121506.json"}},{"package":{"name":"ntpsec","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/ntpsec?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.3+dfsg1-8ubuntu2","1.2.3+dfsg1-8ubuntu3"],"ecosystem_specific":{"binaries":[{"binary_name":"ntpsec","binary_version":"1.2.3+dfsg1-8ubuntu3"},{"binary_version":"1.2.3+dfsg1-8ubuntu3","binary_name":"ntpsec-ntpdate"},{"binary_name":"ntpsec-ntpdig","binary_version":"1.2.3+dfsg1-8ubuntu3"},{"binary_name":"ntpsec-ntpviz","binary_version":"1.2.3+dfsg1-8ubuntu3"},{"binary_version":"1.2.3+dfsg1-8ubuntu3","binary_name":"python3-ntp"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121506.json"}},{"package":{"name":"ntpsec","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/ntpsec?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.3+dfsg1-8ubuntu1","1.2.3+dfsg1-8ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"ntpsec","binary_version":"1.2.3+dfsg1-8ubuntu2"},{"binary_name":"ntpsec-ntpdate","binary_version":"1.2.3+dfsg1-8ubuntu2"},{"binary_name":"ntpsec-ntpdig","binary_version":"1.2.3+dfsg1-8ubuntu2"},{"binary_version":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