CVE-2020-1747A vulnerability was discovered in the PyYAML library in versions before 5.3.1, where it is susceptible to arbitrary code execution when it…
- 9.8CriticalCVSS base score
- 5.4%Exploitation in 30 daysEPSS · top 7.1% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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
ID reserved
By redhat
- 4 months later
· 4 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 5.4% · top 7.1% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIpyyamlGHSA-6757-jp84-gxfx (opens in a new tab)
References
References10
- FEDORA-2020-40c35d7b37 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2020-bdb0bfa928 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2020-e9741a6a15 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- openSUSE-SU-2020:0507 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- openSUSE-SU-2020:0630 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- FEDORA-2021-3342569a0f (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2021-eed7193502 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- https://www.oracle.com/security-alerts/cpujul2022.html (opens in a new tab)x_refsource_MISCx_transferred
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1747 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/yaml/pyyaml/pull/386 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2020-0160 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-6757-jp84-gxfx (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-1747)Record last updated .