CVE-2021-28902: Cesnet Libyang

High severity, CVSS 7.5. EPSS: 1.6% chance of exploitation in the next 30 days.

In function read_yin_container() in libyang <= v1.0.225, it doesn't check whether the value of retval->ext[r] is NULL. In some cases, it can be NULL, which leads to the operation of retval->ext[r]->flags that results in a crash.

Affected products

• Cesnet Libyang: up to and including 1.0.225

Published 2021-05-20. Last modified 2026-06-17.