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

Source: https://junglewise.ai/threats/cve-2026-12545-a-flaw-was-found-in-rubygem-hammer-cli-a-command-injection  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-01. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-12545 · Severity: medium · CVSS 6.7 · Published 2026-10-01

Hammer CLI is a command-line interface tool for managing Red Hat Satellite, a system management platform used by enterprises. A flaw in how Hammer CLI invokes the user's text editor allows an attacker to execute arbitrary shell commands by manipulating the $EDITOR environment variable, potentially leading to unauthorized access or control of systems managed through Satellite.

Vendors: [Ruby](https://junglewise.ai/threats/vendors/ruby).

## Quick answers

**Is CVE-2026-12545 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-12545 being exploited in the wild.

**How severe is CVE-2026-12545?** Medium severity, with a CVSS score of 6.7, published 1 October 2026.

**Which products and versions are affected?** Ruby Hammer Cli <UNKNOWN>.

**Is there a fix for CVE-2026-12545?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-12545 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-12545?** Check whether you run Ruby Hammer Cli at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a command injection flaw in rubygem-hammer_cli caused by insecure interpolation of the $EDITOR environment variable into the Ruby system() method. When a single interpolated string is passed to system(), the shell (/bin/sh) interprets metacharacters (;, |, &) allowing command injection. An attacker who can control the $EDITOR environment variable on a system where Hammer CLI is used can achieve arbitrary command execution with the privileges of the CLI user.

## Affected products

- Ruby hammer_cli <UNKNOWN>

## Timeline

- 2026-10-01: disclosed
- 2026-10-01: advisory

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/errata/RHSA-2026:74503](https://access.redhat.com/errata/RHSA-2026:74503)