CVE-2020-14343

highpriority · attend · 51EPSS 0.060 · 93 %ileexploit · PoCDEEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

4 exploits · PoC

Likely / severe?

5.98% (93rd) EPSS

CVSS 10 · high

Is it mine?

17 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-26

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.

cvss

Technical severity, 0–10. One row per scoring source.

10.0

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 9.3–10

v2.010highAV:N/AC:L/Au:N/C:C/I:C/A:Cprimary · NVD / NIST USexploitability 10 · impact 10

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · OSV

v3.19.3criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Psecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-20USCWE-20US

exploits (4)

Public proof-of-concept and weaponised exploit code.

Kairo-one/CVE-2020-14343-PyYAMLCVE-2020-14343的payloadPoC · poc_in_github
j4k0m/loader-CVE-2020-14343A web application vulnerable to CVE-2020-14343 insecure deserialization leading to command execution in PyYAML package.PoC · poc_in_github
saina15/cve-2020-14343-labControlled vulnerability research and reproduction lab for CVE-2020-14343 in PyYAMLPoC · poc_in_github
sijie52/yasa-cve-2020-14343sijie52/yasa-cve-2020-14343PoC · poc_in_github

affected products (17)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Gentoo Linuxall versionscert_bundDEcpe:/o:gentoo:linux:-
Open Source Arch Linuxall versionscert_bundDEcpe:/o:archlinux:archlinux:-
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Red Hat Enterprise Linux 8all versionscert_bundDEcpe:/o:redhat:enterprise_linux:8
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
n/a PyYAML≤ PyYAML 5.4enisa_euvdEU
АО «НППКТ» ОСОН ОСнова Оnyx≤ 2.12fstec_bduRU
ООО «Ред Софт» РЕД ОС≤ 7.2 Муромfstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 4.7fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 1.7fstec_bduRU
Сообщество свободного программного обеспечения PyYAML5.1 → 5.3.1fstec_bduRU
oracle communications cloud native core network function cloud native environment= 1.10.0nvdUScpe:2.3:a:oracle:communications_cloud_native_core_network_function_cloud_native_environment:*:*:*:*:*:*:*:*
oracle communications cloud native core network function cloud native environment= 22.1.0nvdUScpe:2.3:a:oracle:communications_cloud_native_core_network_function_cloud_native_environment:*:*:*:*:*:*:*:*
pyyaml pyyaml5.1 → 5.4nvdUScpe:2.3:a:pyyaml:pyyaml:*:*:*:*:*:*:*:*
PyPI pyyaml< 5.4osvUSpkg:pypi/pyyaml

advisories (4)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2022-0721Red Hat Enterprise Linux: Mehrere SchwachstellenDeutsch2021-06-29csaf · cert_bundDE
Ein entfernter, anonymer, authentifizierter oder lokaler Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um beliebigen Programmcode auszuführen und einen Denial of Service Zustand herzustellen.
WID-SEC-W-2023-1032Oracle PeopleSoft: Mehrere SchwachstellenDeutsch2023-04-18csaf · cert_bundDE
Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle PeopleSoft ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.
GHSA-8q59-q68h-6hv4Improper Input Validation in PyYAML2021-03-25ghsa · osvUS
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.
PYSEC-2021-1422021-02-09vendor · osvUS
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.

also known as (7)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv cert_bund nvd NVD CVE.org MITRE

published 2021-02-09modified 2026-06-17

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references (26)

External citations — patches, advisories, analysis.

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