check-branches is vulnerable to command Injection

published 2025-09-30 13 mo ago modified 2026-06-17 4 mo ago also GHSA-9c4g-fp4r-prrv , EUVD-2025-31701

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.4%; EPSS 1.4% chance of exploitation in 30 days, percentile 71%
public exploits: 0; none known

All versions of the package check-branches are vulnerable to Command Injection check-branches is a command-line tool that is interacted with locally, or via CI, to confirm no conflicts exist in git branches. However, the library follows these conventions which can be abused: 1. It trusts branch names as they are (plain text) 2. It spawns git commands by concatenating user input Since a branch name is potentially a user input - as users can create branches remotely via pull requests, or simply due to privileged access to a repository - it can effectively be abused to run any command.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: total
Assessed: 13 mo ago (2025-09-30)

Exploit prediction

1.35% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	check-branches	<=0.0.19	no fix listed

Affected products

n/a check-branches

Classification

Weakness

CWE-78 Improper Neutralization of Special Elements used in an OS Command
CWE-77 Improper Neutralization of Special Elements used in a Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary