{"id":"USN-8721-1","summary":"openssh vulnerabilities","details":"It was discovered that OpenSSH's ssh-agent incorrectly handled interactions\nbetween agent locking and the session-bind@openssh.com extension. A remote\nattacker with access to a forwarded agent connection could possibly use\nthis issue to perform operations that should only be available locally,\nsuch as adding tokens or using keys. (CVE-2026-73281)\n\nIt was discovered that OpenSSH's ssh client incorrectly handled concurrent\nremote-forwarding operations. A remote attacker could possibly use this\nissue to cause a use-after-free condition, resulting in a denial of service\nor the execution of arbitrary code. (CVE-2026-73282)\n\nIt was discovered that OpenSSH's sshd server incorrectly applied the\nrestrict keyword from authorized_keys to tunnel forwarding requests. A\nlocal attacker with an authorized key could possibly use this issue to\nbypass intended tunnel forwarding restrictions. (CVE-2026-73283)","modified":"2026-09-03T22:56:55.264832476Z","published":"2026-09-03T12:30:15Z","related":["UBUNTU-CVE-2026-73281","UBUNTU-CVE-2026-73282","UBUNTU-CVE-2026-73283"],"upstream":["CVE-2026-73281","CVE-2026-73282","CVE-2026-73283","UBUNTU-CVE-2026-73281","UBUNTU-CVE-2026-73282","UBUNTU-CVE-2026-73283"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8721-1"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-73281"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-73282"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-73283"}],"affected":[{"package":{"name":"openssh","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/openssh?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:8.9p1-3ubuntu0.17"}]}],"versions":["1:8.4p1-6ubuntu2","1:8.7p1-2","1:8.7p1-2build1","1:8.7p1-4","1:8.8p1-1","1:8.9p1-3","1:8.9p1-3ubuntu0.1","1:8.9p1-3ubuntu0.3","1:8.9p1-3ubuntu0.4","1:8.9p1-3ubuntu0.5","1:8.9p1-3ubuntu0.6","1:8.9p1-3ubuntu0.7","1:8.9p1-3ubuntu0.10","1:8.9p1-3ubuntu0.11","1:8.9p1-3ubuntu0.13","1:8.9p1-3ubuntu0.14","1:8.9p1-3ubuntu0.15","1:8.9p1-3ubuntu0.16"],"ecosystem_specific":{"binaries":[{"binary_name":"openssh-client","binary_version":"1:8.9p1-3ubuntu0.17"},{"binary_name":"openssh-server","binary_version":"1:8.9p1-3ubuntu0.17"},{"binary_version":"1:8.9p1-3ubuntu0.17","binary_name":"openssh-sftp-server"},{"binary_version":"1:8.9p1-3ubuntu0.17","binary_name":"openssh-tests"},{"binary_name":"ssh","binary_version":"1:8.9p1-3ubuntu0.17"},{"binary_version":"1:8.9p1-3ubuntu0.17","binary_name":"ssh-askpass-gnome"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8721-1.json","cves_map":{"cves":[{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}],"id":"CVE-2026-73281"},{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"},{"score":"medium","type":"Ubuntu"}],"id":"CVE-2026-73282"},{"id":"CVE-2026-73283","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N"},{"score":"medium","type":"Ubuntu"}]}],"ecosystem":"Ubuntu:22.04:LTS"}}},{"package":{"name":"openssh","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/openssh?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.6p1-3ubuntu13.19"}]}],"versions":["1:9.3p1-1ubuntu3","1:9.4p1-1ubuntu1","1:9.6p1-3ubuntu1","1:9.6p1-3ubuntu2","1:9.6p1-3ubuntu11","1:9.6p1-3ubuntu12","1:9.6p1-3ubuntu13","1:9.6p1-3ubuntu13.3","1:9.6p1-3ubuntu13.4","1:9.6p1-3ubuntu13.5","1:9.6p1-3ubuntu13.7","1:9.6p1-3ubuntu13.8","1:9.6p1-3ubuntu13.9","1:9.6p1-3ubuntu13.11","1:9.6p1-3ubuntu13.12","1:9.6p1-3ubuntu13.13","1:9.6p1-3ubuntu13.14","1:9.6p1-3ubuntu13.15","1:9.6p1-3ubuntu13.16","1:9.6p1-3ubuntu13.18"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"openssh-client","binary_version":"1:9.6p1-3ubuntu13.19"},{"binary_name":"openssh-server","binary_version":"1:9.6p1-3ubuntu13.19"},{"binary_name":"openssh-sftp-server","binary_version":"1:9.6p1-3ubuntu13.19"},{"binary_name":"openssh-tests","binary_version":"1:9.6p1-3ubuntu13.19"},{"binary_version":"1:9.6p1-3ubuntu13.19","binary_name":"ssh"},{"binary_version":"1:9.6p1-3ubuntu13.19","binary_name":"ssh-askpass-gnome"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8721-1.json","cves_map":{"ecosystem":"Ubuntu:24.04:LTS","cves":[{"id":"CVE-2026-73281","severity":[{"score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]},{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"},{"score":"medium","type":"Ubuntu"}],"id":"CVE-2026-73282"},{"id":"CVE-2026-73283","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N"},{"score":"medium","type":"Ubuntu"}]}]}}},{"package":{"name":"openssh","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/openssh?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:10.2p1-2ubuntu3.6"}]}],"versions":["1:10.0p1-5ubuntu5","1:10.2p1-2ubuntu1","1:10.2p1-2ubuntu3","1:10.2p1-2ubuntu3.2","1:10.2p1-2ubuntu3.4","1:10.2p1-2ubuntu3.5"],"ecosystem_specific":{"binaries":[{"binary_name":"openssh-client","binary_version":"1:10.2p1-2ubuntu3.6"},{"binary_name":"openssh-client-gssapi","binary_version":"1:10.2p1-2ubuntu3.6"},{"binary_version":"1:10.2p1-2ubuntu3.6","binary_name":"openssh-server"},{"binary_version":"1:10.2p1-2ubuntu3.6","binary_name":"openssh-server-gssapi"},{"binary_name":"openssh-sftp-server","binary_version":"1:10.2p1-2ubuntu3.6"},{"binary_name":"openssh-tests","binary_version":"1:10.2p1-2ubuntu3.6"},{"binary_name":"ssh","binary_version":"1:10.2p1-2ubuntu3.6"},{"binary_version":"1:10.2p1-2ubuntu3.6","binary_name":"ssh-askpass-gnome"}],"availability":"No subscription required"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:26.04:LTS","cves":[{"id":"CVE-2026-73281","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]},{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"},{"type":"Ubuntu","score":"medium"}],"id":"CVE-2026-73282"},{"id":"CVE-2026-73283","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8721-1.json"}}],"schema_version":"1.9.0"}