CVE-2020-14343
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...
- Published
- Feb 9, 2021
- Updated
- Aug 4, 2024
- Assigning CNA
- redhat
- Evidence observed
- Aug 8, 2026
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLow · next 30 days
- Percentile
- 93.0%
- Model date
- Sep 21, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
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.
Sources
4Controlled vulnerability research and reproduction lab for CVE-2020-14343 in PyYAML
A web application vulnerable to CVE-2020-14343 insecure deserialization leading to command execution in PyYAML package.
- CVE-2020-14343-PyYAMLExploit
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