Is CVE-2026-114134 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-114134 being exploited in the wild.

How severe is CVE-2026-114134?

High severity, with a CVSS score of 4, published 5 November 2026.

Which products and versions are affected?

black (PyPI) < 26.10.1, ECOSYSTEM:introduced=0,fixed=26.10.1; Python Software Foundation Black < 26.10.1.

Is there a fix for CVE-2026-114134?

Yes. black (PyPI): upgrade to 26.10.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-114134 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-114134?

Check whether you run black (PyPI) or Python Software Foundation Black at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-114134: Black GitHub Action code injection via unvalidated required-version

Q: Which products and versions are affected?

black (PyPI) < 26.10.1, ECOSYSTEM:introduced=0,fixed=26.10.1; Python Software Foundation Black < 26.10.1.

Q: Is there a fix for CVE-2026-114134?

Yes. black (PyPI): upgrade to 26.10.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-114134 attacked?

It is attacked over the network, in a hosted service.

Q: Am I affected by CVE-2026-114134?

Check whether you run black (PyPI) or Python Software Foundation Black at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-114134 · Severity: high · CVSS 4 · Published 2026-11-05

Black is a popular Python code formatter. Its bundled GitHub Action, when configured with the use_pyproject setting enabled, accepts package version specifications from pyproject.toml without validation. An attacker can modify this file in a pull request to point to a malicious code repository, allowing arbitrary code execution in the victim's CI/CD workflow.

Technologies: black (PyPI). Vendors: PyPI, Python Software Foundation.

Quick answers

Is CVE-2026-114134 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-114134 being exploited in the wild.
How severe is CVE-2026-114134?: High severity, with a CVSS score of 4, published 5 November 2026.
Which products and versions are affected?: black (PyPI) < 26.10.1, ECOSYSTEM:introduced=0,fixed=26.10.1; Python Software Foundation Black < 26.10.1.
Is there a fix for CVE-2026-114134?: Yes. black (PyPI): upgrade to 26.10.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-114134 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-114134?: Check whether you run black (PyPI) or Python Software Foundation Black at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

black (PyPI): upgrade to 26.10.1 or later
```
pip install "black>=26.10.1"
```

Technical details

The Black GitHub Action fails to validate the tool.black.required-version field when use_pyproject is set to True, allowing arbitrary Python package installation from attacker-controlled repositories. An attacker with write access to a repository (or via a crafted pull request) can modify pyproject.toml to inject a malicious version string that pip will install without restrictions. This grants remote code execution in the GitHub Actions runner context with the privileges of the workflow.

Affected products

Python Software Foundation Black < 26.10.1

Identifiers

CVE-2026-114134
GHSA-cg8m-r9f2-5wm2

Timeline

2026-10-22: disclosed
2026-10-22: advisory

References

https://api.github.com/users/jiteshgulati

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