CVE-2026-67279
SSH Pre-Authentication Rekey State Bypass in MikroTik RouterOS
KEVMEDIUM 6.9EPSS 1.0%
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)
- Affected
- Mikrotik · RouterOS
- CVSS v4.0 CERT
- 6.9 MEDIUM
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/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 - CVSS v3.1 NVD
- 6.5 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - EPSS
- 1.03% chance of exploitation in the next 30 days, 63rd percentile
- CISA KEV
- added 2026-09-25
- Published
- 2026-09-05
- Updated
- 2026-09-26
Proof-of-concept exploits (5)
- https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldn…
- gagaltotal/CVE-2026-mikrotik-poc3★ · 2026-10-08
- HackSpeak/CVE-2026-672794★ · 2026-09-26
- tc4dy/CVE-2026-67279-86060-Toolkit3★ · 2026-10-12
- shmaki4/CVE-2026-67279-Mikrotik-6.42-POC0★ · 2026-10-08
Security advisories
- https://mikrotik.com/supportsec/september-2026-vulnerability
- https://bishopfox.com/blog/mikrotrick-inside-the-routeros-takeover-chain
- https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve
- https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited
- https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldn…
- https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
- https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
- https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800