{"id":"UBUNTU-CVE-2026-25834","details":"Mbed TLS v3.3.0 up to 3.6.5 and 4.0.0 allows Algorithm Downgrade.","modified":"2026-05-20T16:24:47.450700739Z","published":"2026-04-01T18:16:00Z","upstream":["CVE-2026-25834"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-25834"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-25834"}],"affected":[{"package":{"name":"mbedtls","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/mbedtls?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.1.2-1","2.2.0-1","2.2.1-1","2.2.1-2","2.2.1-2ubuntu0.1","2.2.1-2ubuntu0.2","2.2.1-2ubuntu0.3"],"ecosystem_specific":{"binaries":[{"binary_version":"2.2.1-2ubuntu0.3","binary_name":"libmbedcrypto0"},{"binary_version":"2.2.1-2ubuntu0.3","binary_name":"libmbedtls10"},{"binary_name":"libmbedx509-0","binary_version":"2.2.1-2ubuntu0.3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-25834.json"}},{"package":{"name":"mbedtls","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/mbedtls?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.5.1-1ubuntu1","2.6.0-1","2.7.0-2","2.8.0-1","2.8.0-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libmbedcrypto1","binary_version":"2.8.0-1ubuntu0.1~esm1"},{"binary_name":"libmbedtls10","binary_version":"2.8.0-1ubuntu0.1~esm1"},{"binary_version":"2.8.0-1ubuntu0.1~esm1","binary_name":"libmbedx509-0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-25834.json"}},{"package":{"name":"mbedtls","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/mbedtls?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.16.2-1","2.16.3-1","2.16.4-1ubuntu2","2.16.4-1ubuntu2+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.16.4-1ubuntu2+esm1","binary_name":"libmbedcrypto3"},{"binary_version":"2.16.4-1ubuntu2+esm1","binary_name":"libmbedtls12"},{"binary_name":"libmbedx509-0","binary_version":"2.16.4-1ubuntu2+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-25834.json"}},{"package":{"name":"mbedtls","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/mbedtls?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.16.9-0.1ubuntu1","2.16.11-0.1ubuntu1","2.16.11-0.3","2.28.0-1","2.28.0-1build1","2.28.0-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libmbedcrypto7","binary_version":"2.28.0-1ubuntu0.1~esm1"},{"binary_version":"2.28.0-1ubuntu0.1~esm1","binary_name":"libmbedtls14"},{"binary_name":"libmbedx509-1","binary_version":"2.28.0-1ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-25834.json"}},{"package":{"name":"mbedtls","ecosystem":"Ubuntu:Pro:24.04:LTS","purl":"pkg:deb/ubuntu/mbedtls?arch=source&distro=esm-apps%2Fnoble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.28.3-1","2.28.6-1ubuntu1","2.28.7-1ubuntu1","2.28.7-1.1ubuntu1","2.28.8-1","2.28.8-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.28.8-1ubuntu0.1~esm1","binary_name":"libmbedcrypto7t64"},{"binary_name":"libmbedtls14t64","binary_version":"2.28.8-1ubuntu0.1~esm1"},{"binary_name":"libmbedx509-1t64","binary_version":"2.28.8-1ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-25834.json"}},{"package":{"name":"mbedtls","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/mbedtls?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.6.2-3ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.6.2-3ubuntu1","binary_name":"libmbedcrypto16"},{"binary_name":"libmbedtls21","binary_version":"3.6.2-3ubuntu1"},{"binary_name":"libmbedx509-7","binary_version":"3.6.2-3ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-25834.json"}},{"package":{"name":"mbedtls","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/mbedtls?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.6.2-3ubuntu1","3.6.5-0.1ubuntu1","3.6.5-0.1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"libmbedcrypto16","binary_version":"3.6.5-0.1ubuntu2"},{"binary_name":"libmbedtls21","binary_version":"3.6.5-0.1ubuntu2"},{"binary_version":"3.6.5-0.1ubuntu2","binary_name":"libmbedx509-7"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-25834.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L"},{"type":"Ubuntu","score":"medium"}]}