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Fencer Vulns
critical 9.9

CVE-2026-26068 json

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

published 2026-02-12 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-7373

cvss
9.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.7%
EPSS 3.7% chance of exploitation in 30 days, percentile 89%
public exploits
0
none known

Summary

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.

Patch / fix

  • jm33-m0 emp3r0r 3.21.1

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
8 mo ago

Exploit prediction

3.74% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/jm33-m0/emp3r0r/security/advisories/GHSA-h5p4-4xp4-vjpp referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 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
CNA 4.0 9.3 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

  • jm33-m0 emp3r0r

Classification

Weakness
  • CWE-77 Improper Neutralization of Special Elements used in a Command
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.