CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVE-2020-1747
Critical (9.8). EPSS 5.4% chance of exploitation in the next 30 days. Fixed in pyyaml 5.3.1.
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.
Severity
- EPSS
- 5.4% chance of exploitation in the next 30 days; higher than 92% of CVEs (scores of 2026-10-31)
- CWE
- CWE-20
- Published
- Modified
- Record from
- the NVD, synced
Affected
- fedoraproject:fedora
- opensuse:leap
- oracle:communications_cloud_native_core_network_function_cloud_native_environment
- pyyaml:pyyaml
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-6757-jp84-gxfx | PyPI | pyyaml | >=5.1b7 <5.3.1 | 5.3.1 |
| PYSEC-2020-96 | PyPI | pyyaml | >=5.1 <5.3.1 | 5.3.1 |
References
- http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00017.html
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00017.html
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1747
- https://github.com/yaml/pyyaml/pull/386
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7PPAS6C4SZRDQLR7C22A5U3QOLXY33JX/