CVE-2026-67279
SSH Pre-Authentication Rekey State Bypass in MikroTik RouterOS
MikroTik·RouterOS
- Added
- Sep 25, 2026
- Fix due
- Sep 28, 2026
- Ransomware
- Not known
- Published
- Sep 5, 2026
- Updated
- Sep 26, 2026
- First covered
- Sep 25, 2026
- Latest story
- 2 months ago
Summary
RouterOS SSH enters the connection protocol after a client-requested rekey even though user authentication was never attempted, allowing an unauthenticated client to open a session channel and send an exec request. On affected builds the server dispatches the command, enabling unauthenticated creation, overwrite, and reconstruction of files in the RouterOS managed file namespace, including support files containing configuration and diagnostic data.This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)
CWE-841Improper enforcement of behavioral workflow
Attack profile
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NCISA required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Affected products
- Mikrotik RouterOS7.24 to before 7.24.27.0.0 to before 7.23.46.0.0 to before 6.49.21