# CVE-2026-12545: Rubygem-hammer_cli: command injection via insecure editor invocation

> Attackers can execute arbitrary commands via shell metacharacters in the EDITOR variable due to insecure system() usage in Hammer CLI.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 1 Oct 2026
- **Updated:** 7 Oct 2026
- **Also known as:** GHSA-q4vv-h3wg-pwgx

## What is CVE-2026-12545?

CVE-2026-12545 is a medium-severity command injection vulnerability in Red Hat Satellite 6, published on 1 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A flaw was found in rubygem-hammer_cli. A command injection vulnerability exists in Hammer CLI and the Railties (Ruby on Rails) component distributed with Satellite due to the insecure interpolation of the $EDITOR environment variable into the Ruby system() method. By passing a single interpolated string to system(), the application invokes a system shell (/bin/sh) that interprets shell metacharacters (e.g., ;, |, &).

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-12545?


## How do I fix CVE-2026-12545?

Apply the vendor's patch.

## Is CVE-2026-12545 being exploited?

There is no known exploitation of CVE-2026-12545 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12545 and fix it if it is affected.

What it is: CVE-2026-12545 is a medium-severity command injection vulnerability in Red Hat Satellite 6, published on 1 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-12545 in the wild and no public exploit code.

Affected product: Red Hat Satellite 6. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-12545/ (Markdown: https://insights.sbomify.com/CVE-2026-12545/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12545
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12545
- OSV: https://osv.dev/vulnerability/CVE-2026-12545

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-12545/
Summaries are generated and may contain mistakes; the official description above is the record.