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)

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Mikrotik RouterOS unaffected
Version Status Constraints
7.24 affected < 7.24.2
7.0.0 affected < 7.23.4
6.0.0 affected < 6.49.21

No data.

No data.

No data.

Project Subscriptions

Vendors Products
Mikrotik Subscribe
Routeros Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve cve-icon cve-icon
https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ cve-icon cve-icon
https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802 cve-icon cve-icon
https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 cve-icon cve-icon
https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 cve-icon cve-icon
https://mikrotik.com/supportsec/september-2026-vulnerability/ cve-icon cve-icon
https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ cve-icon cve-icon
History

Sat, 05 Sep 2026 20:45:00 +0000

Type Values Removed Values Added
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 (Lont-term), 7.23.4 (Lont-term) and 7.24.2 (Stable) 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)

Sat, 05 Sep 2026 20:15:00 +0000

Type Values Removed Values Added
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 (Lont-term), 7.23.4 (Lont-term) and 7.24.2 (Stable)
Title SSH Pre-Authentication Rekey State Bypass in MikroTik RouterOS
First Time appeared Mikrotik
Mikrotik routeros
Weaknesses CWE-841
CPEs cpe:2.3:a:mikrotik:routeros:*:*:*:*:*:*:*:*
Vendors & Products Mikrotik
Mikrotik routeros
References
Metrics cvssV4_0

{'score': 6.9, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: CERT-PL

Published:

Updated: 2026-09-05T20:40:29.029Z

Reserved: 2026-07-29T11:59:30.538Z

Link: CVE-2026-67279

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-05T20:17:18.390

Modified: 2026-09-05T20:17:18.390

Link: CVE-2026-67279

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses