CVE-2021-39207

Name: CVE-2021-39207
Creator: NVD / NIST
Published: 2021-09-10T23:15:07.343+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.74%

Last modified Jun 17, 2026

CVE-2021-39207 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. parlai is a framework for training and evaluating AI models on a variety of openly available dialogue datasets. In affected versions the package is vulnerable to YAML deserialization attack caused by unsafe loading which leads to Arbitary code execution. EPSS estimates a 1.74% chance of exploitation in the next 30 days.

Description

parlai is a framework for training and evaluating AI models on a variety of openly available dialogue datasets. In affected versions the package is vulnerable to YAML deserialization attack caused by unsafe loading which leads to Arbitary code execution. This security bug is patched by avoiding unsafe loader users should update to version above v1.1.0. If upgrading is not possible then users can change the Loader used to SafeLoader as a workaround. See commit 507d066ef432ea27d3e201da08009872a2f37725 for details.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

1.74%

74.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-502

Affected Software

Vendor	Product	Versions
Facebook	Parlai	< 1.1.0

References

https://github.com/facebookresearch/ParlAI/commit/4374fa2aba383db6526ab36e939eb1cf8ef99879Patch, Third Party Advisory
https://github.com/facebookresearch/ParlAI/commit/507d066ef432ea27d3e201da08009872a2f37725Patch, Third Party Advisory
https://github.com/facebookresearch/ParlAI/security/advisories/GHSA-m87f-9fvv-2mggPatch, Third Party Advisory
https://github.com/facebookresearch/ParlAI/commit/4374fa2aba383db6526ab36e939eb1cf8ef99879Patch, Third Party Advisory
https://github.com/facebookresearch/ParlAI/commit/507d066ef432ea27d3e201da08009872a2f37725Patch, 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-2021-39207?

How severe is CVE-2021-39207?

CVE-2021-39207 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.74% probability of exploitation in the next 30 days.

How do I fix CVE-2021-39207?

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-2021-39207?

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

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Source: NVD / NIST