willitmerge has a Command Injection vulnerability

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X · score source

EPSS

• CVE-2025-66219: 2.66% estimated exploitation activity in the next 30 days; percentile 85.71 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

willitmerge describes itself as a command line tool to check if pull requests are mergeable. There is a Command Injection vulnerability in version willitmerge@0.2.1. Resources: Project's GitHub source code: https://github.com/shama/willitmerge/ Project's npm package: https://www.npmjs.com/package/willitmerge Background on exploitation Reporting a Command Injection vulnerability in willitmerge npm package. A security vulnerability manifests in this package due to the use of insecure child process execution API (exec) to which it concateanes user input, whether provided to the command-line flag, or is in user control in the target repository. Exploit POC 1 1. Install willitmerge 2. Run it with the following command 3. Confirm the file /tmp/hel is created on disk GitHub-sourced attack vector Lines 189-197 in lib/willitmerge.js pass user input controlled by repository collaborators into the git command: Users creating malicious branch names such as ;{echo,hello,world}/tmp/c This is a…

Published by the source

26 Nov 2025, 22:09 UTC

Last modified by the source

1 Dec 2025, 17:03 UTC

Source last checked

26 Oct 2026, 12:38 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-j9wj-m24m-7jj6

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-j9wj-m24m-7jj6

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# Patch Next advisory brief: CVE-2025-66219

Advisory: willitmerge has a Command Injection vulnerability
IDs: CVE-2025-66219, GHSA-j9wj-m24m-7jj6
Record: https://patchnext.com/advisories/cve-2025-66219 (revision 3, source checked 26 Oct 2026, 12:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm willitmerge: affected <= 0.2.1

## Suggested inspection (read-only)
- `npm ls willitmerge --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on willitmerge.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-j9wj-m24m-7jj6 (OSV record GHSA-j9wj-m24m-7jj6 lists affected ranges: npm willitmerge >=0 <=0.2.1)
- Verified: https://github.com/advisories/GHSA-j9wj-m24m-7jj6 (GitHub-reviewed advisory GHSA-j9wj-m24m-7jj6 lists affected ranges: npm willitmerge >=0 <=0.2.1)

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