{"id":"UBUNTU-CVE-2019-20398","details":"A NULL pointer dereference is present in libyang before v1.0-r3 in the function lys_extension_instances_free() due to a copy of unresolved extensions in lys_restr_dup(). Applications that use libyang to parse untrusted input yang files may crash.","modified":"2025-10-24T04:48:08Z","published":"2020-01-22T22:15:00Z","upstream":["CVE-2019-20398"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2019-20398"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1793935"},{"type":"REPORT","url":"https://github.com/CESNET/libyang/commit/7852b272ef77f8098c35deea6c6f09cb78176f08"},{"type":"REPORT","url":"https://github.com/CESNET/libyang/issues/773"},{"type":"REPORT","url":"https://github.com/CESNET/libyang/compare/v1.0-r2...v1.0-r3"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2019-20398"}],"affected":[{"package":{"name":"libyang","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libyang@0.16.105-3build1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.16.105-1","0.16.105-2","0.16.105-3","0.16.105-3build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyang-cpp-dev","binary_version":"0.16.105-3build1"},{"binary_name":"libyang-cpp0.16","binary_version":"0.16.105-3build1"},{"binary_name":"libyang-dev","binary_version":"0.16.105-3build1"},{"binary_name":"libyang0.16","binary_version":"0.16.105-3build1"},{"binary_name":"python3-yang","binary_version":"0.16.105-3build1"},{"binary_name":"yang-tools","binary_version":"0.16.105-3build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2019/UBUNTU-CVE-2019-20398.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}