Vulnerability · Published Feb 12, 2026 · Assigned by GitHub_M

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

Critical 9.3

In plain English

A critical-severity command injection in emp3r0r from jm33-m0. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 3.8% (higher than 90% of all known vulnerabilities).

Severity (CVSS 4.0)9.3Critical

Exploit odds (30 days)3.8%top 10.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
jm33-m0	emp3r0r	< 3.21.1

Weakness: CWE-77, CWE-78 · 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

References

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