CVE-2026-31900
Fixed in a distro release EPSS <1%CVSS 8.7
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.
Products: psf black
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| PyPI | black | 26.3.0 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | black | no fix |
| Debian 13 | black | no fix |
| Debian 14 | black | no fix |
| SUSE Linux Enterprise Server 16.0 | python-black | 25.1.0-160000.3.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | python-black | 25.1.0-160000.3.1 |
| Ubuntu 20.04 LTS | black | no fix |
| Ubuntu 22.04 LTS | black | no fix |
| Ubuntu 24.04 LTS | black | no fix |
| Ubuntu 25.10 | black | no fix |
| Ubuntu 26.04 LTS | black | no fix |
| Ubuntu 26.10 | black | no fix |
| openSUSE Leap 16.0 | python-black | 25.1.0-160000.3.1 |
| openSUSE Tumbleweed | python-black | 26.3.1-1.1 |