{"id":"UBUNTU-CVE-2026-40194","details":"phpseclib is a PHP secure communications library. Starting in 0.1.1 and prior to 3.0.51, 2.0.53, and 1.0.28, phpseclib\\Net\\SSH2::get_binary_packet() uses PHP's != operator to compare a received SSH packet HMAC against the locally computed HMAC. != on equal-length binary strings in PHP uses memcmp(), which short-circuits on the first differing byte. This is a real variable-time comparison (CWE-208), proven by scaling benchmarks. This vulnerability is fixed in 3.0.51, 2.0.53, and 1.0.28.","modified":"2026-09-15T20:16:39.538845947Z","published":"2026-04-10T21:16:00Z","upstream":["CVE-2026-40194"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-40194"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-40194"},{"type":"REPORT","url":"https://github.com/phpseclib/phpseclib/security/advisories/GHSA-r854-jrxh-36qx"},{"type":"REPORT","url":"https://github.com/phpseclib/phpseclib/commit/ffe48b6b1b1af6963327f0a5330e3aa004a194ac"},{"type":"REPORT","url":"https://github.com/phpseclib/phpseclib/releases/tag/1.0.28"},{"type":"REPORT","url":"https://github.com/phpseclib/phpseclib/releases/tag/2.0.53"},{"type":"REPORT","url":"https://github.com/phpseclib/phpseclib/releases/tag/3.0.51"}],"affected":[{"package":{"name":"php-phpseclib","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/php-phpseclib?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.1-1","2.0.1-1build1","2.0.1-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"2.0.1-1ubuntu0.1~esm2","binary_name":"php-phpseclib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40194.json"}},{"package":{"name":"phpseclib","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/phpseclib?arch=source&distro=esm-apps-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.3.10-3","1.0.0-2","1.0.0-3","1.0.1-1","1.0.1-3","1.0.1-3ubuntu0.1","1.0.1-3ubuntu0.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"php-seclib","binary_version":"1.0.1-3ubuntu0.1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40194.json"}},{"package":{"name":"php-phpseclib","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/php-phpseclib?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.6-1","2.0.7-1","2.0.9-1","2.0.9-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"2.0.9-1ubuntu0.1~esm2","binary_name":"php-phpseclib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40194.json"}},{"package":{"name":"phpseclib","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/phpseclib?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.7-1","1.0.8-1","1.0.9-1","1.0.9-1ubuntu0.1~esm1","1.0.9-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.0.9-1ubuntu0.1~esm2","binary_name":"php-seclib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40194.json"}},{"package":{"name":"php-phpseclib","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/php-phpseclib?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.21-2","2.0.23-2","2.0.23-2ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"php-phpseclib","binary_version":"2.0.23-2ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40194.json"}},{"package":{"name":"phpseclib","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/phpseclib?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.16-2","1.0.18-2","1.0.18-2ubuntu0.1~esm1","1.0.18-2ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.0.18-2ubuntu0.1~esm2","binary_name":"php-seclib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40194.json"}},{"package":{"name":"php-phpseclib","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/php-phpseclib?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.30-2ubuntu1","2.0.34-1","2.0.35-1","2.0.36-1","2.0.36-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"2.0.36-1ubuntu0.1~esm2","binary_name":"php-phpseclib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40194.json"}},{"package":{"name":"php-phpseclib3","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/php-phpseclib3?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.9-1","3.0.10-1","3.0.12-2","3.0.13-1","3.0.13-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.0.13-1ubuntu0.1~esm1","binary_name":"php-phpseclib3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4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medium"}]}