CVE-2021-24040

Name: CVE-2021-24040
Creator: NVD / NIST
Published: 2021-09-10T22:15:07.443+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 17.35%

Last modified Jun 17, 2026

CVE-2021-24040 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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.. EPSS estimates a 17.35% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

17.35%

96.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Facebook	Parlai	< 1.1.0

References

http://packetstormsecurity.com/files/164136/Facebook-ParlAI-1.0.0-Code-Execution-Deserialization.htmlExploit, Third Party Advisory, VDB Entry
https://github.com/facebookresearch/ParlAI/releases/tag/v1.1.0Release Notes, Third Party Advisory
https://github.com/facebookresearch/ParlAI/security/advisories/GHSA-m87f-9fvv-2mggPatch, Third Party Advisory
http://packetstormsecurity.com/files/164136/Facebook-ParlAI-1.0.0-Code-Execution-Deserialization.htmlExploit, Third Party Advisory, VDB Entry
https://github.com/facebookresearch/ParlAI/releases/tag/v1.1.0Release Notes, Third Party Advisory
https://github.com/facebookresearch/ParlAI/security/advisories/GHSA-m87f-9fvv-2mggPatch, Third Party Advisory

Timeline

Published: Sep 10, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-24040?

How severe is CVE-2021-24040?

CVE-2021-24040 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 17.35% probability of exploitation in the next 30 days.

How do I fix CVE-2021-24040?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-24040?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST