CVE-2026-31900

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. 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.

9.8 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/psf/black/commit/0a2560b981364dde4c8cf8ce9d164c40669a8611 Patch
https://github.com/psf/black/security/advisories/GHSA-v53h-f6m7-xcgm Mitigation Vendor Advisory
Configurations

Configuration 1 (hide)

cpe:2.3:a:python:black:*:*:*:*:*:*:*:*
History

16 Mar 2026, 20:02

Type Values Removed Values Added
References () https://github.com/psf/black/commit/0a2560b981364dde4c8cf8ce9d164c40669a8611 - () https://github.com/psf/black/commit/0a2560b981364dde4c8cf8ce9d164c40669a8611 - Patch
References () https://github.com/psf/black/security/advisories/GHSA-v53h-f6m7-xcgm - () https://github.com/psf/black/security/advisories/GHSA-v53h-f6m7-xcgm - Mitigation, Vendor Advisory
CPE cpe:2.3:a:python:black:*:*:*:*:*:*:*:*
Summary
  • (es) Black es el formateador de código Python intransigente. Black proporciona una acción de GitHub para formatear código. Esta acción admite una opción, use_pyproject: true, para leer la versión de Black a utilizar desde el archivo pyproject.toml del repositorio. Una solicitud de extracción maliciosa podría editar pyproject.toml para usar una referencia de URL directa a un repositorio malicioso. Esto podría conducir a la ejecución de código arbitrario en el contexto de la Acción de GitHub. Los atacantes podrían entonces obtener acceso a secretos o permisos disponibles en el contexto de la acción. La versión 26.3.0 corrige esta vulnerabilidad.
CWE NVD-CWE-noinfo
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 9.8
First Time Python
Python black

11 Mar 2026, 20:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-03-11 20:16

Updated : 2026-03-16 20:02

NVD link : CVE-2026-31900

Mitre link : CVE-2026-31900

CVE.ORG link : CVE-2026-31900

JSON object : View

Products Affected

python

  • black
CWE
CWE-20

Improper Input Validation

NVD-CWE-noinfo