CVE-2019-20477: Fedoraproject Fedora

Critical severity, CVSS 9.8. EPSS: 5.1% chance of exploitation in the next 30 days.

PyYAML 5.1 through 5.1.2 has insufficient restrictions on the load and load_all functions because of a class deserialization issue, e.g., Popen is a class in the subprocess module. NOTE: this issue exists because of an incomplete fix for CVE-2017-18342.

Affected products

• Fedoraproject Fedora: version 30 only; version 31 only
• Pyyaml Pyyaml: from 5.1, up to and including 5.1.2

Published 2020-02-19. Last modified 2026-06-17.