CVE-2026-114134

high

Description

Black is the uncompromising Python code formatter. Prior to 26.10.1, the Black GitHub Action with use_pyproject: true accepts tool.black.required-version from pyproject.toml without validating that it is a released Black version specifier. An attacker who can submit a pull request can change that field to a direct reference to attacker-controlled code, causing the workflow to install and execute the code in the victim repository's GitHub Actions context. This issue is fixed in version 26.10.1.

References

https://github.com/psf/black/security/advisories/GHSA-cg8m-r9f2-5wm2

https://github.com/psf/black/pull/5510

https://github.com/psf/black/commit/ac1f71563aeccf73cf13ece00f231d9d6c66a514

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-117785

Details

Source: Mitre, NVD

Published: 2026-11-05

Updated: 2026-11-12

Named Vulnerability: GHSA-cg8m-r9f2-5wm2

Risk Information

CVSS v2

Base Score: 9.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:P/A:C

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00404