{"cve":"CVE-2019-20398","nvd":{"published":"2020-01-22T22:15:10.627","modified":"2026-06-17T02:30:21.860","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-476"],"references":["https://bugzilla.redhat.com/show_bug.cgi?id=1793935","https://github.com/CESNET/libyang/commit/7852b272ef77f8098c35deea6c6f09cb78176f08","https://github.com/CESNET/libyang/compare/v1.0-r2...v1.0-r3","https://github.com/CESNET/libyang/issues/773","https://lists.debian.org/debian-lts-announce/2023/09/msg00019.html"],"products":["cesnet:libyang"],"source":"nvd","synced_at":"2026-10-19T21:01:01.339895972+00:00"},"epss":{"cve":"CVE-2019-20398","score":0.01818,"percentile":0.78728,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}