CVE-2026-31900
Black is the uncompromising Python code formatter. Black provides a GitHub action for formatting code. This action supports an option, use_pyproject: true, for reading the version of Black to use from the repository pyproject.toml. A malicious pull request could edit pyproject.toml to use a direct URL reference to a malicious repository. This could lead to arbitrary code execution in the context of the GitHub Action. Attackers could then gain access to secrets or permissions available in the context of the action. Version 26.3.0 fixes this vulnerability.
Exploitation Probability (EPSS)
Low PriorityThe Exploit Prediction Scoring System (EPSS) uses machine learning to estimate the probability that a vulnerability will be exploited in the wild within the next 30 days.
7-Day Exploitation Trend
Vulnerability Timeline
2 eventsThreat Actor Attribution
PREMIUM INTELRemediation & Mitigation
SOLUTIONOfficial patches and mitigation steps are available for this vulnerability.
apt-get update && apt-get upgrade -y specific-package
# Verify installation
dpkg -l | grep package-name
Affected Products
Am I Vulnerable?
Check your domain or package.json for CVE-2026-31900 exposure.
Vulnerability Details
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