No exploitation reportedFix available

CVE-2020-1747

No exploitation reported by the sources we read.

Published2020-03-24
WeaknessCWE-20

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability was discovered in the PyYAML library in versions before 5.3.1, 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. An attacker could use this flaw to execute arbitrary code on the system by abusing the python/object/new constructor.

Timeline

dates in UTC

2020-03-2415:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-1747?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-1747?format=csv
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Versions per branch

NVD

Fedoraproject fedora

Branch	Affected	Fixed in	Source
30.x	= 30	no fix published	NVD
31.x	= 31	no fix published	NVD
32.x	= 32	no fix published	NVD
33.x	= 33	no fix published	NVD

Opensuse leap

Branch	Affected	Fixed in	Source
15.1	= 15.1	no fix published	NVD

Oracle communications cloud native core network function cloud native environment

Branch	Affected	Fixed in	Source
22.1	= 22.1.0	no fix published	NVD

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.19.8read 2026-10-23
NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.010read 2026-10-23
CNAweakness (CWE)CWE-20read 2026-10-23
NVDweakness (CWE)CWE-20read 2026-10-23
FIRST EPSSEPSS score5.4 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2020-03-24
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-1747?

Is CVE-2020-1747 actively exploited?

Active exploitation of CVE-2020-1747 has not been confirmed. Its EPSS score was 5.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-1747?

CVE-2020-1747 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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