Mikrotik RouterOS up to 6.49.20/7.23.3/7.24.1 SSH Connection Protocol improper authentication

Summaryinfo

A vulnerability has been found in Mikrotik RouterOS up to 6.49.20/7.23.3/7.24.1 and classified as very critical. Affected by this issue is some unknown functionality of the component SSH Connection Protocol. This manipulation causes improper authentication. This vulnerability is tracked as CVE-2026-67279. The attack is possible to be carried out remotely. Moreover, an exploit is present. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as very critical was found in Mikrotik RouterOS up to 6.49.20/7.23.3/7.24.1. Affected by this vulnerability is an unknown part of the component SSH Connection Protocol. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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)

It is possible to read the advisory at cert.pl. This vulnerability is known as CVE-2026-67279 since 07/29/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are unknown but an exploit is available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/25/2026).

It is declared as attacked. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 09/25/2026 with a due date of 09/28/2026:

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 BO

Upgrading to version 6.49.21, 7.23.4 or 7.24.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-72027). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Mikrotik

Name

• RouterOS

Version

• 6.49.0
• 6.49.1
• 6.49.2
• 6.49.3
• 6.49.4
• 6.49.5
• 6.49.6
• 6.49.7
• 6.49.8
• 6.49.9
• 6.49.10
• 6.49.11
• 6.49.12
• 6.49.13
• 6.49.14
• 6.49.15
• 6.49.16
• 6.49.17
• 6.49.18
• 6.49.19
• 6.49.20
• 7.23.0
• 7.23.1
• 7.23.2
• 7.23.3
• 7.24.0
• 7.24.1

License

• commercial

CPE 2.3info

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CPE 2.2info

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Be aware that VulDB is the high quality source for vulnerability data.

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