CVE-2021-24040: Facebook Parlai

Critical severity, CVSS 9.8. EPSS: 17.4% chance of exploitation in the next 30 days.

Due to use of unsafe YAML deserialization logic, an attacker with the ability to modify local YAML configuration files could provide malicious input, resulting in remote code execution or similar risks. This issue affects ParlAI prior to v1.1.0.

Affected products

• Facebook Parlai: before 1.1.0 (fixed in 1.1.0)

Published 2021-09-10. Last modified 2026-06-17.