CVE-2019-20397: Cesnet Libyang

High severity, CVSS 8.8. EPSS: 2.5% chance of exploitation in the next 30 days.

A double-free is present in libyang before v1.0-r1 in the function yyparse() when an organization field is not terminated. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.

Affected products

• Cesnet Libyang: version 0.11 only; version 0.12 only; version 0.13 only; version 0.14 only; version 0.15 only; version 0.16 only

Published 2020-01-22. Last modified 2026-06-17.