{"id":"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":"2026-08-07T14:53:11.113239Z","published":"2020-01-22T22:15:10.627Z","references":[{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2023/09/msg00019.html"},{"type":"ADVISORY","url":"https://github.com/CESNET/libyang/compare/v1.0-r2...v1.0-r3"},{"type":"FIX","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1793935"},{"type":"FIX","url":"https://github.com/CESNET/libyang/commit/7852b272ef77f8098c35deea6c6f09cb78176f08"},{"type":"EVIDENCE","url":"https://github.com/CESNET/libyang/issues/773"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/cesnet/libyang","events":[{"introduced":"14a95280b2bd77b5fd1d9b5f8af71b15679f1a8f"},{"last_affected":"347246611b85e05d16f54faaa5697c4b2ee4b468"},{"fixed":"7852b272ef77f8098c35deea6c6f09cb78176f08"}],"database_specific":{"cpe":["cpe:2.3:a:cesnet:libyang:0.11:r1:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.11:r2:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.12:r1:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.12:r2:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.13:r1:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.13:r2:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.14:r1:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.15:r1:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.16:r1:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.16:r2:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:0.16:r3:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:1.0:r1:*:*:*:*:*:*","cpe:2.3:a:cesnet:libyang:1.0:r2:*:*:*:*:*:*"],"extracted_events":[{"introduced":"0.11-r1"},{"last_affected":"0.11-r1"},{"introduced":"0.11-r2"},{"last_affected":"0.11-r2"},{"introduced":"0.12-r1"},{"last_affected":"0.12-r1"},{"introduced":"0.12-r2"},{"last_affected":"0.12-r2"},{"introduced":"0.13-r1"},{"last_affected":"0.13-r1"},{"introduced":"0.13-r2"},{"last_affected":"0.13-r2"},{"introduced":"0.14-r1"},{"last_affected":"0.14-r1"},{"introduced":"0.15-r1"},{"last_affected":"0.15-r1"},{"introduced":"0.16-r1"},{"last_affected":"0.16-r1"},{"introduced":"0.16-r2"},{"last_affected":"0.16-r2"},{"introduced":"0.16-r3"},{"last_affected":"0.16-r3"},{"introduced":"1.0-r1"},{"last_affected":"1.0-r1"},{"introduced":"1.0-r2"},{"last_affected":"1.0-r2"}],"source":["CPE_STRING","REFERENCES"]}}],"versions":["0.11-r1","0.11-r2","0.12-r1","0.12-r2","0.13-r1","0.13-r2","0.14-r1","0.15-r1","0.16-r1","0.16-r2","0.16-r3","1.0-r1","1.0-r2","v1.0-r2","v1.0-r1","v0.16-r2","v0.16-r1","v0.15-r1","v0.14-r1","v0.13-r2","v0.12-r2","v0.12-r1","v0.11-r2","v0.11-r1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-20398.json","vanir_signatures_modified":"2026-08-07T14:53:11Z","vanir_signatures":[{"signature_version":"v1","source":"https://github.com/cesnet/libyang/commit/7852b272ef77f8098c35deea6c6f09cb78176f08","target":{"file":"src/tree_schema.c"},"deprecated":false,"digest":{"line_hashes":["47057829883453850662777565401974008433","2962779122798403009016500093738661883","35155857828643995570069637654412522537","177345036629041976534470018548302784898","33582507515680815319481015823527354523"],"threshold":0.9},"id":"CVE-2019-20398-599ecb19","signature_type":"Line"},{"source":"https://github.com/cesnet/libyang/commit/7852b272ef77f8098c35deea6c6f09cb78176f08","target":{"file":"src/tree_schema.c","function":"lys_restr_dup"},"deprecated":false,"digest":{"function_hash":"310547109486459982374848703543419293865","length":909},"id":"CVE-2019-20398-b0f6280f","signature_type":"Function","signature_version":"v1"}]}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"}]}