CVE-2020-14343

Name: CVE-2020-14343
Creator: NVD / NIST
Published: 2021-02-09T21:15:12.707+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 5.98%

Last modified Jun 17, 2026

CVE-2020-14343 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. A vulnerability was discovered in the PyYAML library in versions before 5.4, where it is susceptible to arbitrary code execution when it processes untrusted YAML files through the full_load method or with the FullLoader loader. Applications that use the library to process untrusted input may be vulnerable to this flaw. EPSS estimates a 5.98% chance of exploitation in the next 30 days.

Description

A vulnerability was discovered in the PyYAML library in versions before 5.4, where it is susceptible to arbitrary code execution when it processes untrusted YAML files through the full_load method or with the FullLoader loader. Applications that use the library to process untrusted input may be vulnerable to this flaw. This flaw allows an attacker to execute arbitrary code on the system by abusing the python/object/new constructor. This flaw is due to an incomplete fix for CVE-2020-1747.

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

5.98%

92.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Pyyaml	Pyyaml	>= 5.1, < 5.4
Oracle	Communications Cloud Native Core Network Function Cloud Native Environment	1.10.0
Oracle	Communications Cloud Native Core Network Function Cloud Native Environment	22.1.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1860466Issue Tracking, Third Party Advisory
https://github.com/SeldonIO/seldon-core/issues/2252
https://github.com/yaml/pyyaml/issues/420
https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1860466Issue Tracking, Third Party Advisory
https://github.com/SeldonIO/seldon-core/issues/2252
https://github.com/yaml/pyyaml/issues/420
https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch, Third Party Advisory

Timeline

Published: Feb 9, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-14343?

How severe is CVE-2020-14343?

CVE-2020-14343 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 5.98% probability of exploitation in the next 30 days.

How do I fix CVE-2020-14343?

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-2020-14343?

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

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Source: NVD / NIST