{"id":"UBUNTU-CVE-2026-59846","details":"A flaw was found in libssh. A malicious username expanded through %r in ProxyCommand handling can inject shell metacharacters, exposing environment variables and causing unintended shell behavior.","modified":"2026-08-31T17:16:50.291436481Z","published":"2026-07-21T13:17:00Z","related":["USN-8699-1"],"upstream":["CVE-2026-59846"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-59846"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-59846"},{"type":"REPORT","url":"https://www.libssh.org/2026/07/21/libssh-0-12-1-and-0-11-5-security-releases/"},{"type":"REPORT","url":"https://www.libssh.org/security/advisories/CVE-2026-59846.txt"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8699-1"}],"affected":[{"package":{"name":"libssh","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/libssh?arch=source&distro=esm-infra%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.6.3-3ubuntu3","0.6.3-4.1","0.6.3-4.2","0.6.3-4.2ubuntu1","0.6.3-4.3","0.6.3-4.3ubuntu0.1","0.6.3-4.3ubuntu0.2","0.6.3-4.3ubuntu0.5","0.6.3-4.3ubuntu0.6","0.6.3-4.3ubuntu0.6+esm1","0.6.3-4.3ubuntu0.6+esm2","0.6.3-4.3ubuntu0.6+esm3","0.6.3-4.3ubuntu0.6+esm4","0.6.3-4.3ubuntu0.6+esm5"],"ecosystem_specific":{"binaries":[{"binary_name":"libssh-4","binary_version":"0.6.3-4.3ubuntu0.6+esm5"},{"binary_version":"0.6.3-4.3ubuntu0.6+esm5","binary_name":"libssh-gcrypt-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-59846.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/libssh?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.7.5-1","0.8.0~20170825.94fa1e38-1","0.8.0~20170825.94fa1e38-1build1","0.8.0~20170825.94fa1e38-1ubuntu0.1","0.8.0~20170825.94fa1e38-1ubuntu0.2","0.8.0~20170825.94fa1e38-1ubuntu0.5","0.8.0~20170825.94fa1e38-1ubuntu0.6","0.8.0~20170825.94fa1e38-1ubuntu0.7","0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3","0.8.0~20170825.94fa1e38-1ubuntu0.7+esm4","0.8.0~20170825.94fa1e38-1ubuntu0.7+esm5","0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6","0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"],"ecosystem_specific":{"binaries":[{"binary_version":"0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7","binary_name":"libssh-4"},{"binary_name":"libssh-gcrypt-4","binary_version":"0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-59846.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/libssh?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.9.0-1ubuntu1","0.9.0-1ubuntu4","0.9.0-1ubuntu5","0.9.3-2ubuntu1","0.9.3-2ubuntu2","0.9.3-2ubuntu2.1","0.9.3-2ubuntu2.2","0.9.3-2ubuntu2.3","0.9.3-2ubuntu2.4","0.9.3-2ubuntu2.5","0.9.3-2ubuntu2.5+esm1","0.9.3-2ubuntu2.5+esm2","0.9.3-2ubuntu2.5+esm3","0.9.3-2ubuntu2.5+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"libssh-4","binary_version":"0.9.3-2ubuntu2.5+esm4"},{"binary_name":"libssh-gcrypt-4","binary_version":"0.9.3-2ubuntu2.5+esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-59846.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libssh?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.6-2ubuntu0.22.04.8"}]}],"versions":["0.9.6-1","0.9.6-1build1","0.9.6-2","0.9.6-2build1","0.9.6-2ubuntu0.22.04.1","0.9.6-2ubuntu0.22.04.2","0.9.6-2ubuntu0.22.04.3","0.9.6-2ubuntu0.22.04.4","0.9.6-2ubuntu0.22.04.5","0.9.6-2ubuntu0.22.04.6","0.9.6-2ubuntu0.22.04.7"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"0.9.6-2ubuntu0.22.04.8","binary_name":"libssh-4"},{"binary_version":"0.9.6-2ubuntu0.22.04.8","binary_name":"libssh-gcrypt-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-59846.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libssh?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.10.6-2ubuntu0.5"}]}],"versions":["0.10.5-3ubuntu1","0.10.5-3ubuntu2","0.10.6-2","0.10.6-2build1","0.10.6-2build2","0.10.6-2ubuntu0.1","0.10.6-2ubuntu0.2","0.10.6-2ubuntu0.3","0.10.6-2ubuntu0.4"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libssh-4","binary_version":"0.10.6-2ubuntu0.5"},{"binary_version":"0.10.6-2ubuntu0.5","binary_name":"libssh-gcrypt-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-59846.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libssh?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.11.3-1ubuntu2.1"}]}],"versions":["0.11.2-1build1","0.11.3-1","0.11.3-1ubuntu1","0.11.3-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_version":"0.11.3-1ubuntu2.1","binary_name":"libssh-4"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-59846.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}