CVE-2021-27213: Pystemon Project Pystemon

Critical severity, CVSS 9.8. EPSS: 2.6% chance of exploitation in the next 30 days.

config.py in pystemon before 2021-02-13 allows code execution via YAML deserialization because SafeLoader and safe_load are not used.

Affected products

• Pystemon Project Pystemon: before 2021-02-13 (fixed in 2021-02-13)

Published 2021-02-14. Last modified 2026-06-17.