Security vulnerability detected: pyyaml #142
Description
This issue tracks security vulnerabilities detected by Dependabot for pyyaml. We need to update the packages, and apply code fixes where necessary in the application. We need to pin the package version to the latest version compatible with the application code, but not any newer. We also need to add a FIX_SUMMARY.md file which describes what was fixed in the pull request.
Dependabot Alert #10 - Security vulnerability in pyyaml
Summary: Improper Input Validation in PyYAML
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.
Severity: critical
Fixed in: 5.3.1
More details: Security Advisory
Full Vulnerability Details
{
"number": 10,
"state": "open",
"dependency": {
"package": {
"ecosystem": "pip",
"name": "pyyaml"
},
"manifest_path": "requirements/prd.txt",
"scope": "runtime",
"relationship": "unknown"
},
"security_advisory": {
"ghsa_id": "GHSA-6757-jp84-gxfx",
"cve_id": "CVE-2020-1747",
"summary": "Improper Input Validation in PyYAML",
"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.",
"severity": "critical",
"identifiers": [
{
"value": "GHSA-6757-jp84-gxfx",
"type": "GHSA"
},
{
"value": "CVE-2020-1747",
"type": "CVE"
}
],
"references": [
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-1747"
},
{
"url": "https://github.com/yaml/pyyaml/pull/386"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1747"
},
{
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00017.html"
},
{
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00017.html"
},
{
"url": "https://www.oracle.com/security-alerts/cpujul2022.html"
},
{
"url": "https://github.com/yaml/pyyaml/commit/5080ba513377b6355a0502104846ee804656f1e0"
},
{
"url": "https://github.com/advisories/GHSA-6757-jp84-gxfx"
},
{
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/pyyaml/PYSEC-2020-96.yaml"
},
{
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7PPAS6C4SZRDQLR7C22A5U3QOLXY33JX"
},
{
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/K5HEPD7LEVDPCITY5IMDYWXUMX37VFMY"
},
{
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MMQXSZXNJT6ERABJZAAICI3DQSQLCP3D"
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{
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WORRFHPQVAFKKXXWLSSW6XKUYLWM6CSH"
},
{
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZBJA3SGNJKCAYPSHOHWY3KBCWNM5NYK2"
},
{
"url": "https://github.com/github/advisory-database/pull/4942"
},
{
"url": "https://github.com/yaml/pyyaml/commit/0cedb2a0697b2bc49e4f3841b8d4590b6b15657e"
}
],
"published_at": "2021-04-20T16:14:24Z",
"updated_at": "2024-10-31T16:18:25Z",
"withdrawn_at": null,
"vulnerabilities": [
{
"package": {
"ecosystem": "pip",
"name": "pyyaml"
},
"severity": "critical",
"vulnerable_version_range": ">= 5.1b7, < 5.3.1",
"first_patched_version": {
"identifier": "5.3.1"
}
}
],
"cvss_severities": {
"cvss_v3": {
"vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"score": 9.8
},
"cvss_v4": {
"vector_string": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"score": 9.3
}
},
"epss": {
"percentage": 0.02593,
"percentile": 0.84989
},
"cvss": {
"vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"score": 9.8
},
"cwes": [
{
"cwe_id": "CWE-20",
"name": "Improper Input Validation"
}
]
},
"security_vulnerability": {
"package": {
"ecosystem": "pip",
"name": "pyyaml"
},
"severity": "critical",
"vulnerable_version_range": ">= 5.1b7, < 5.3.1",
"first_patched_version": {
"identifier": "5.3.1"
}
},
"url": "https://api.github.com/repos/arthurthlee/testing/dependabot/alerts/10",
"html_url": "https://github.com/arthurthlee/testing/security/dependabot/10",
"created_at": "2025-08-22T17:14:16Z",
"updated_at": "2025-08-28T23:40:43Z",
"dismissed_at": null,
"dismissed_by": null,
"dismissed_reason": null,
"dismissed_comment": null,
"fixed_at": null,
"auto_dismissed_at": null
}
Dependabot Alert #2 - Security vulnerability in pyyaml
Summary: Deserialization of Untrusted Data in PyYAML
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.
Severity: critical
Fixed in: 5.2
More details: Security Advisory
Full Vulnerability Details
{
"number": 2,
"state": "open",
"dependency": {
"package": {
"ecosystem": "pip",
"name": "pyyaml"
},
"manifest_path": "requirements/prd.txt",
"scope": "runtime",
"relationship": "unknown"
},
"security_advisory": {
"ghsa_id": "GHSA-3pqx-4fqf-j49f",
"cve_id": "CVE-2019-20477",
"summary": "Deserialization of Untrusted Data in PyYAML",
"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.",
"severity": "critical",
"identifiers": [
{
"value": "GHSA-3pqx-4fqf-j49f",
"type": "GHSA"
},
{
"value": "CVE-2019-20477",
"type": "CVE"
}
],
"references": [
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-20477"
},
{
"url": "https://github.com/yaml/pyyaml/blob/master/CHANGES"
},
{
"url": "https://www.exploit-db.com/download/47655"
},
{
"url": "https://github.com/advisories/GHSA-3pqx-4fqf-j49f"
},
{
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/pyyaml/PYSEC-2020-176.yaml"
},
{
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/33VBUY73AA6CTTYL3LRWHNFDULV7PFPN"
},
{
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/52N5XS73Z5S4ZN7I7R56ICCPCTKCUV4H"
}
],
"published_at": "2021-04-20T16:40:42Z",
"updated_at": "2024-10-25T21:15:15Z",
"withdrawn_at": null,
"vulnerabilities": [
{
"package": {
"ecosystem": "pip",
"name": "pyyaml"
},
"severity": "critical",
"vulnerable_version_range": ">= 5.1, < 5.2",
"first_patched_version": {
"identifier": "5.2"
}
}
],
"cvss_severities": {
"cvss_v3": {
"vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"score": 9.8
},
"cvss_v4": {
"vector_string": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"score": 9.3
}
},
"epss": {
"percentage": 0.00518,
"percentile": 0.65725
},
"cvss": {
"vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"score": 9.8
},
"cwes": [
{
"cwe_id": "CWE-502",
"name": "Deserialization of Untrusted Data"
}
]
},
"security_vulnerability": {
"package": {
"ecosystem": "pip",
"name": "pyyaml"
},
"severity": "critical",
"vulnerable_version_range": ">= 5.1, < 5.2",
"first_patched_version": {
"identifier": "5.2"
}
},
"url": "https://api.github.com/repos/arthurthlee/testing/dependabot/alerts/2",
"html_url": "https://github.com/arthurthlee/testing/security/dependabot/2",
"created_at": "2025-08-22T17:14:15Z",
"updated_at": "2025-08-28T23:40:43Z",
"dismissed_at": null,
"dismissed_by": null,
"dismissed_reason": null,
"dismissed_comment": null,
"fixed_at": null,
"auto_dismissed_at": null
}
Dependabot Alert #1 - Security vulnerability in PyYAML
Summary: Improper Input Validation in PyYAML
Description: 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.
Severity: critical
Fixed in: 5.4
More details: Security Advisory
Full Vulnerability Details
{
"number": 1,
"state": "open",
"dependency": {
"package": {
"ecosystem": "pip",
"name": "PyYAML"
},
"manifest_path": "requirements/prd.txt",
"scope": "runtime",
"relationship": "unknown"
},
"security_advisory": {
"ghsa_id": "GHSA-8q59-q68h-6hv4",
"cve_id": "CVE-2020-14343",
"summary": "Improper Input Validation in PyYAML",
"description": "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.",
"severity": "critical",
"identifiers": [
{
"value": "GHSA-8q59-q68h-6hv4",
"type": "GHSA"
},
{
"value": "CVE-2020-14343",
"type": "CVE"
}
],
"references": [
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-14343"
},
{
"url": "https://github.com/yaml/pyyaml/commit/a001f2782501ad2d24986959f0239a354675f9dc"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=1860466"
},
{
"url": "https://github.com/yaml/pyyaml/issues/420#issuecomment-663673966"
},
{
"url": "https://www.oracle.com/security-alerts/cpuapr2022.html"
},
{
"url": "https://www.oracle.com/security-alerts/cpujul2022.html"
},
{
"url": "https://github.com/SeldonIO/seldon-core/issues/2252"
},
{
"url": "https://github.com/yaml/pyyaml/issues/420"
},
{
"url": "https://github.com/advisories/GHSA-8q59-q68h-6hv4"
},
{
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/pyyaml/PYSEC-2021-142.yaml"
},
{
"url": "https://pypi.org/project/PyYAML"
}
],
"published_at": "2021-03-25T21:26:26Z",
"updated_at": "2024-10-25T21:31:46Z",
"withdrawn_at": null,
"vulnerabilities": [
{
"package": {
"ecosystem": "pip",
"name": "PyYAML"
},
"severity": "critical",
"vulnerable_version_range": "< 5.4",
"first_patched_version": {
"identifier": "5.4"
}
}
],
"cvss_severities": {
"cvss_v3": {
"vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"score": 9.8
},
"cvss_v4": {
"vector_string": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"score": 9.3
}
},
"epss": {
"percentage": 0.13704,
"percentile": 0.94
},
"cvss": {
"vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"score": 9.8
},
"cwes": [
{
"cwe_id": "CWE-20",
"name": "Improper Input Validation"
}
]
},
"security_vulnerability": {
"package": {
"ecosystem": "pip",
"name": "PyYAML"
},
"severity": "critical",
"vulnerable_version_range": "< 5.4",
"first_patched_version": {
"identifier": "5.4"
}
},
"url": "https://api.github.com/repos/arthurthlee/testing/dependabot/alerts/1",
"html_url": "https://github.com/arthurthlee/testing/security/dependabot/1",
"created_at": "2025-08-22T17:14:15Z",
"updated_at": "2025-08-28T23:40:43Z",
"dismissed_at": null,
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"fixed_at": null,
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}