How severe is CVE-2020-15142?

CVE-2020-15142 has a CVSS score of 9/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-15142?

CVE-2020-15142 affects the following packages: openapi-python-client (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2020-15142?

Update openapi-python-client to 0.5.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15142 is resolved across your whole dependency graph.

How do I detect CVE-2020-15142 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openapi-python-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-15142 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2020-15142 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-15142 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2020-15142?

CVE-2020-15142 has an EPSS (Exploit Prediction Scoring System) score of 1.8%, placing it in the 78th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2020-15142?

CVE-2020-15142 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2020-15142 published, and has it been updated?

CVE-2020-15142 was published on August 14, 2020 and was last updated on August 27, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

CRITICAL severity

CVE-2020-15142 — openapi-python-client

CRITICALFix: triaxtec/openapi-python-client@f7a56aa

CVE-2020-15142 is a critical-severity (CVSS 9) Code Injection vulnerability in openapi-python-client. A fix is available for openapi-python-client — see the affected versions and patch details below.

openapi-python-client Arbitrary Code Generation vulnerability

Also known asGHSA-9x4c-63pf-525fPYSEC-2020-71

Published

Aug 14, 2020

Updated

Aug 27, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 28, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs78th percentile — riskier than 78% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2020-15142 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐍openapi-python-client

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

Clients generated with a maliciously crafted OpenAPI Document can generate arbitrary Python code. Subsequent execution of this malicious client is arbitrary code execution.

Giving this a CVSS of 8.0 (high) with CVSS:3.0/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:U/RC:C .

Patches

Fix will be included in version 0.5.3

Workarounds

Inspect OpenAPI documents before generating, or inspect generated code before executing.

For more information

If you have any questions or comments about this advisory:

Open an issue in openapi-python-client
Email us at [email protected]

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`openapi-python-client`	all versions	0.5.3`pip install --upgrade 'openapi-python-client==0.5.3'`

Affected Products

1 product · 1 configurations

Application

openapi-python-clientopenapi-python-client_project

< 0.5.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openapi-python-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update openapi-python-client to 0.5.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15142 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

### Impact Clients generated with a maliciously crafted OpenAPI Document can generate arbitrary Python code. Subsequent execution of this malicious client is arbitrary code execution. Giving this a CVSS of 8.0 (high) with CVSS:3.0/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:U/RC:C . ### Patches Fix will be included in version 0.5.3 ### Workarounds Inspect OpenAPI documents before generating, or inspect generated code before executing. ### For more information If you have any questions or comments about this advisory: * Open an issue in [openapi-python-client](https://github.com/triaxtec/ope