MikroTik · RouterOS
CVE-2026-67279
SSH Pre-Authentication Rekey State Bypass in MikroTik RouterOS
Qué es
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)
CISA: Mikrotik RouterOS contains an improper enforcement of behavioral workflow vulnerability that could allow an unauthenticated client to open a session channel and send an exec request. This vulnerability can be chained to achieve unauthenticated exploitation of CVE-2026-86060.
Qué hacer
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.
Plazo para las agencias federales de EE. UU.: 28 de septiembre de 2026
- Añadida a la lista de CISA
- 25 de septiembre de 2026
- Publicada
- 5 de septiembre de 2026
- Gravedad
- Media 6,9 CVSS 4.0
- Probabilidad de ataques en los próximos 30 días (EPSS)
- 2,3% entre el 17,0% superior de todas las vulnerabilidades conocidas
- Debilidad
- CWE-841
- Más detalles
- NVD · CVE.org · CISA
Todas las referencias (7)
- https://mikrotik.com/supportsec/september-2026-vulnerability/
- 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-wouldnt-explain/
- 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
Más fallos explotados de MikroTik
| Añadido | Vulnerabilidad | Producto | Gravedad | Prob. de ataque |
|---|---|---|---|---|
| 10 sept 2026 | Missing Authentication for Critical Function | RouterOS | Alto 8,8 | 1,6% |
| 10 sept 2026 | Improper Neutralization of Argument Delimiters in a Command | RouterOS | Crítica 9,2 | 6,4% |
| 8 sept 2022 | Stack-Based Buffer Overflow | RouterOS | Crítica 9,8 | 66% |
| 1 dic 2021 | Router OS Directory Traversal | RouterOS | Crítica 9,1 | 96% |
Fuentes: Known Exploited Vulnerabilities (CISA, dominio público), CVE records (cve.org) y EPSS (FIRST). La probabilidad de ataque es la estimación EPSS de que alguien intente explotar el fallo en los próximos 30 días.