Summary
generated automatically from NVD dataMikroTik RouterOS's SSH service has a flaw (CWE-841) where, after a client-requested rekey, the server enters the connection protocol even though user authentication never took place. An unauthenticated client can then open a session channel and send an exec request, letting it create, overwrite and reconstruct files in the RouterOS managed file namespace, including support files with configuration and diagnostic data. The issue is rated 6.5 (MEDIUM, CVSS v3.1), is listed in the CISA KEV catalog, and was fixed in 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable).
NVD 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)
⚠️ Actively exploited — CISA KEV
This CVE was added to CISA's Known Exploited Vulnerabilities catalog on 2026-09-25. It is confirmed exploited in the wild and must be patched as a priority.
Remediation deadline (US federal agencies): 2026-09-28
EPSS · FIRST.org
1.0%probability of exploitation in the next 30 days
Higher than 62% of scored CVEs
EPSS (Exploit Prediction Scoring System) estimates, from observed exploitation activity, how likely a CVE is to be exploited in the next 30 days. It complements CVSS, which measures severity, not likelihood. Score of 2026-10-16, recomputed daily by FIRST.org.
In-depth analysis on cveo.tech
We've published a detailed analysis of this CVE — exploitation, IOCs and mitigation.
CVSS v3.1 Score
Information
- Published
- 5 sept. 2026
- Updated
- 26 sept. 2026
- Status
- Analyzed
- Source
- cvd@cert.pl
Affected products
Weaknesses (CWE)
References (9)
- https://cert.pl/en/posts/2026/09/mikrotik-routeros-cveThird Party Advisory
- https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/MitigationThird Party Advisory
- https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ExploitThird Party Advisory
- https://bishopfox.com/blog/mikrotrick-inside-the-routeros-takeover-chainThird Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67279US Government Resource
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