critical
CVE-2019-20477
PyYAML: command execution through python/object/apply constructor in FullLoader
In the Trivy database since at least 24 Oct 2026, 07:11 UTCWhen it arrived before that build is not recorded.
Severity by source
NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GHSA9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Red Hat9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Trivy's own label is CRITICAL. Rated critical by NVD, GHSA, Photon OS. Rated lower by Red Hat (medium), AlmaLinux (medium), Oracle (medium), Rocky Linux (medium).
Description
PyYAML 5.1 through 5.1.2 has insufficient restrictions on the load and load_all functions because of a class deserialization issue, e.g., Popen is a class in the subprocess module. NOTE: this issue exists because of an incomplete fix for CVE-2017-18342.
Affected packages and fixed versions
| Source | Package | Fixed in |
|---|---|---|
| Photon OS 1.0 | PyYAML | 3.12-4.ph1 |
| Photon OS 2.0 | PyYAML | 3.12-5.ph2 |
| Photon OS 3.0 | PyYAML | 3.13-4.ph3 |
| pip::GitHub Security Advisory pip | pyyaml | 5.2 |
| alma 8 | python38:3.8::python38-Cython, python38:3.8::python38-asn1crypto, python38:3.8::python38-cffi and 13 more | 0.29.14-4.module_el8.6.0+2778+cd494b30 and 13 more |
| debian 11 | pyyaml | 5.2-1 |
| debian 12 | pyyaml | 5.2-1 |
| debian 13 | pyyaml | 5.2-1 |
| debian 14 | pyyaml | 5.2-1 |
| echo | pyyaml | 5.2-1 |
| Oracle Linux 8 | python38, python38-Cython, python38-PyMySQL and 39 more | 3.8.3-3.module+el8.3.0+7824+e0098946 and 27 more |
| Red Hat | PyYAML | no fix listed |
Show all 100 entries from 14 sources
| Source | Package | Fixed in |
|---|---|---|
| Photon OS 1.0 | PyYAML | 3.12-4.ph1 |
| Photon OS 2.0 | PyYAML | 3.12-5.ph2 |
| Photon OS 3.0 | PyYAML | 3.13-4.ph3 |
| pip::GitHub Security Advisory pip | pyyaml | 5.2 |
| alma 8 | python38:3.8::python38-Cython | 0.29.14-4.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-asn1crypto | 1.2.0-3.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-cffi | 1.13.2-3.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-chardet | 3.0.4-19.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-cryptography | 2.8-3.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-idna | 2.8-6.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-markupsafe | 1.1.1-6.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-mod_wsgi | 4.6.8-3.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-psycopg2 | 2.8.4-4.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-psycopg2-doc | 2.8.4-4.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-psycopg2-tests | 2.8.4-4.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-pycparser | 2.19-3.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-pysocks | 1.7.1-4.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-pytz | 2019.3-3.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-requests | 2.22.0-9.module_el8.6.0+2778+cd494b30 |
| alma 8 | python38:3.8::python38-scipy | 1.3.1-4.module_el8.6.0+2778+cd494b30 |
| debian 11 | pyyaml | 5.2-1 |
| debian 12 | pyyaml | 5.2-1 |
| debian 13 | pyyaml | 5.2-1 |
| debian 14 | pyyaml | 5.2-1 |
| echo | pyyaml | 5.2-1 |
| Oracle Linux 8 | python38 | 3.8.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-Cython | 0.29.14-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-PyMySQL | 0.9.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-asn1crypto | 1.2.0-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-babel | 2.7.0-10.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-cffi | 1.13.2-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-chardet | 3.0.4-19.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-cryptography | 2.8-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-debug | 3.8.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-devel | 3.8.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-idle | 3.8.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-idna | 2.8-6.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-jinja2 | 2.10.3-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-libs | 3.8.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-lxml | 4.4.1-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-markupsafe | 1.1.1-6.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-mod_wsgi | 4.6.8-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-numpy | 1.17.3-5.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-numpy-doc | 1.17.3-5.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-numpy-f2py | 1.17.3-5.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-pip | 19.3.1-1.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-pip-wheel | 19.3.1-1.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-ply | 3.11-8.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-psutil | 5.6.4-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-psycopg2 | 2.8.4-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-psycopg2-doc | 2.8.4-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-psycopg2-tests | 2.8.4-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-pycparser | 2.19-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-pysocks | 1.7.1-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-pytz | 2019.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-pyyaml | 5.3.1-1.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-requests | 2.22.0-9.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-rpm-macros | 3.8.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-scipy | 1.3.1-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-setuptools | 41.6.0-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-setuptools-wheel | 41.6.0-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-six | 1.12.0-9.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-test | 3.8.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-tkinter | 3.8.3-3.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-urllib3 | 1.25.7-4.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-wheel | 0.33.6-5.module+el8.3.0+7824+e0098946 |
| Oracle Linux 8 | python38-wheel-wheel | 0.33.6-5.module+el8.3.0+7824+e0098946 |
| Red Hat | PyYAML | no fix listed |
| rocky 8 | python38:3.8::python38-Cython | 0.29.14-4.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-asn1crypto | 1.2.0-3.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-babel | 2.7.0-10.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-cffi | 1.13.2-3.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-chardet | 3.0.4-19.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-cryptography | 2.8-3.module+el8.5.0+672+ab6eb015 |
| rocky 8 | python38:3.8::python38-idna | 2.8-6.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-jinja2 | 2.10.3-4.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-markupsafe | 1.1.1-6.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-mod_wsgi | 4.6.8-3.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-numpy | 1.17.3-5.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-numpy-doc | 1.17.3-5.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-numpy-f2py | 1.17.3-5.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-pip | 19.3.1-1.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-pip-wheel | 19.3.1-1.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-psutil | 5.6.4-3.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-psycopg2 | 2.8.4-4.module+el8.6.0+794+eba84017 |
| rocky 8 | python38:3.8::python38-psycopg2-doc | 2.8.4-4.module+el8.6.0+794+eba84017 |
| rocky 8 | python38:3.8::python38-psycopg2-tests | 2.8.4-4.module+el8.6.0+794+eba84017 |
| rocky 8 | python38:3.8::python38-pycparser | 2.19-3.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-pysocks | 1.7.1-4.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-pytz | 2019.3-3.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-pyyaml | 5.3.1-1.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-requests | 2.22.0-9.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-scipy | 1.3.1-4.module+el8.5.0+672+ab6eb015 |
| rocky 8 | python38:3.8::python38-setuptools | 41.6.0-4.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-setuptools-wheel | 41.6.0-4.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-urllib3 | 1.25.7-4.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-wheel | 0.33.6-5.module+el8.4.0+570+c2eaf144 |
| rocky 8 | python38:3.8::python38-wheel-wheel | 0.33.6-5.module+el8.4.0+570+c2eaf144 |
| seal pip::Seal Security Database | pyyaml | 5.1+sp999 |
| seal pip::Seal Security Database | seal-pyyaml | 5.1+sp999 |
References
- https://access.redhat.com/errata/RHSA-2020:4641
- https://access.redhat.com/security/cve/CVE-2019-20477
- https://bugzilla.redhat.com/1806005
- https://bugzilla.redhat.com/1807367
- https://bugzilla.redhat.com/1809065
- https://bugzilla.redhat.com/1815643
- https://bugzilla.redhat.com/1847416
- https://bugzilla.redhat.com/1854926
All 36 references
- https://bugzilla.redhat.com/1856481
- https://bugzilla.redhat.com/show_bug.cgi?id=1806005
- https://bugzilla.redhat.com/show_bug.cgi?id=1807367
- https://bugzilla.redhat.com/show_bug.cgi?id=1809065
- https://bugzilla.redhat.com/show_bug.cgi?id=1815643
- https://bugzilla.redhat.com/show_bug.cgi?id=1847416
- https://bugzilla.redhat.com/show_bug.cgi?id=1854926
- https://bugzilla.redhat.com/show_bug.cgi?id=1856481
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-20477
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-20907
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-14422
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-1747
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8492
- https://errata.almalinux.org/8/ALSA-2020-4641.html
- https://errata.rockylinux.org/RLSA-2020:4641
- https://github.com/advisories/GHSA-3pqx-4fqf-j49f
- https://github.com/pypa/advisory-database/tree/main/vulns/pyyaml/PYSEC-2020-176.yaml
- https://github.com/yaml/pyyaml
- https://github.com/yaml/pyyaml/blob/master/CHANGES
- https://linux.oracle.com/cve/CVE-2019-20477.html
- https://linux.oracle.com/errata/ELSA-2020-4641.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/33VBUY73AA6CTTYL3LRWHNFDULV7PFPN
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/33VBUY73AA6CTTYL3LRWHNFDULV7PFPN/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/52N5XS73Z5S4ZN7I7R56ICCPCTKCUV4H
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/52N5XS73Z5S4ZN7I7R56ICCPCTKCUV4H/
- https://nvd.nist.gov/vuln/detail/CVE-2019-20477
- https://www.cve.org/CVERecord?id=CVE-2019-20477
- https://www.exploit-db.com/download/47655