SSH Pre-Authentication Rekey State Bypass in MikroTik RouterOS
Published Sep 5, 2026 ·Due Sep 28, 2026
6.9
MEDIUMCVSS 4.0
EPSS 1.03%
Description
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 products
-
- Version 6.0.0StatusaffectedConstraints<6.49.21
- Version 7.0.0StatusaffectedConstraints<7.23.4
- Version 7.24StatusaffectedConstraints<7.24.2
- Version
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
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
1 other source (NVD) ▾
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
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
Date Added
Sep 25, 2026
Patch Due
Sep 28, 2026
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.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
ActiveAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Sep 25, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Sep–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.03% (0.01027) | 62.32th | v5 (v2026.06.15) |
| Sep 6, 2026 | 0.45% (0.00446) | 37.38th | v5 (v2026.06.15) |
References (9)
- https://bishopfox.com/blog/mikrotrick-inside-the-routeros-takeover-chain third-party-advisory
- https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve third-party-advisory
- https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ technical-description
- https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802 release-notes
- https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 release-notes
- https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 release-notes
- https://mikrotik.com/supportsec/september-2026-vulnerability/ vendor-advisory
- https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ exploit
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67279 government-resource
| Link | Providers | Tags |
|---|---|---|
| https://bishopfox.com/blog/mikrotrick-inside-the-routeros-takeover-chain | third-party-advisory | |
| https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve | third-party-advisory | |
| https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ | technical-description | |
| https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802 | release-notes | |
| https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 | release-notes | |
| https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 | release-notes | |
| https://mikrotik.com/supportsec/september-2026-vulnerability/ | vendor-advisory | |
| https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ | exploit | |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67279 | government-resource |
Change history (7)
- CISA ADP
- SSVC exploitation changed from poc to
active poc → active
- SSVC exploitation changed from poc to
active
- CISA ADP
- SSVC exploitation changed from active to
poc active → poc
- SSVC exploitation changed from active to
poc
- CISA ADP
- SSVC exploitation changed from poc to
active poc → active
- SSVC exploitation changed from poc to
active
- CISA ADP
- SSVC exploitation changed from active to
poc active → poc
- SSVC exploitation changed from active to
poc
- CISA ADP
- SSVC exploitation changed from poc to
active poc → active
- SSVC exploitation changed from poc to
active
- CISA ADP
- SSVC exploitation changed from active to
poc active → poc
- SSVC exploitation changed from active to
poc
- CISA ADP
- SSVC exploitation changed from poc to
active poc → active
- SSVC exploitation changed from poc to
active