wenxian: Command Injection in GitHub Actions Workflow via issue_comment.body

Exploitation

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

CVSS

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

EPSS

• CVE-2026-34243: 2.21% estimated exploitation activity in the next 30 days; percentile 82.62 (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.

Summary A GitHub Actions workflow uses untrusted user input from issuecomment.body directly inside a shell command, allowing potential command injection and arbitrary code execution on the runner. Details The workflow is triggered by issuecomment, which can be controlled by external users. In the following step: the value of github.event.comment.body is directly interpolated into a shell command inside run:. Since GitHub Actions evaluates ${{ }} before execution, attacker-controlled input is injected into the shell context without sanitization. This creates a command injection risk. Additionally, the extracted value is later reused in another step that constructs output using backticks: which may further propagate unsafe content. PoC 1. Go to an issue in the repository 2. Post a comment such as: @njzjz-bot paper123" ) ; whoami ;

3. Observe whether the command is executed or reflected in logs/output <img width="658" height="203" alt="poc"…

Published by the source

29 Mar 2026, 15:39 UTC

Last modified by the source

31 Mar 2026, 18:54 UTC

Source last checked

26 Oct 2026, 17:08 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-r4fj-r33x-8v88

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# Patch Next advisory brief: CVE-2026-34243

Advisory: wenxian: Command Injection in GitHub Actions Workflow via `issue_comment.body`
IDs: CVE-2026-34243, GHSA-r4fj-r33x-8v88
Record: https://patchnext.com/advisories/cve-2026-34243 (revision 1, source checked 26 Oct 2026, 17:08 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
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
- GitHub Actions njzjz/wenxian: affected <= 0.3.1

## Suggested inspection (read-only)
- GitHub Actions njzjz/wenxian: check the installed version with your package manager.

## 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 njzjz/wenxian.
- 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://github.com/advisories/GHSA-r4fj-r33x-8v88 (GitHub-reviewed advisory GHSA-r4fj-r33x-8v88 lists affected ranges: GitHub Actions njzjz/wenxian >=0 <=0.3.1)

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