CVE-2026-67279
medium CISA KEVMikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability
Vendor / product: MikroTik — RouterOS
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)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Required action (CISA)
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
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve cvd@cert.pl
- https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ cvd@cert.pl
- https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802 cvd@cert.pl
- https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 cvd@cert.pl
- https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 cvd@cert.pl
- https://mikrotik.com/supportsec/september-2026-vulnerability/ cvd@cert.pl
- https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt... cvd@cert.pl
- https://bishopfox.com/blog/mikrotrick-inside-the-routeros-takeover-chain 134c704f-9b21-4f2e-91b3-4a467353bcc0
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67279 134c704f-9b21-4f2e-91b3-4a467353bcc0