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.
Metrics
Affected Vendors & Products
References
History
Thu, 12 Mar 2026 20:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Thu, 12 Mar 2026 10:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Psf
Psf black |
|
| Vendors & Products |
Psf
Psf black |
Wed, 11 Mar 2026 19:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Black's vulnerable version parsing leads to RCE in GitHub Action | |
| Weaknesses | CWE-20 | |
| References |
| |
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-03-12T19:59:41.362Z
Reserved: 2026-03-09T21:59:02.689Z
Link: CVE-2026-31900
Updated: 2026-03-12T19:59:38.486Z
Status : Awaiting Analysis
Published: 2026-03-11T20:16:15.960
Modified: 2026-03-12T21:08:22.643
Link: CVE-2026-31900
No data.