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CVE-2026-31900

Black's vulnerable version parsing leads to RCE in GitHub Action PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
psf / blackaffected < 26.3.0

CWE

CWE-20

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.