6.9
MEDIUM CVSS 4.0
CVE-2026-67279
SSH Pre-Authentication Rekey State Bypass in MikroTik RouterOS
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)

INFO

Published Date :

Sept. 5, 2026, 8:17 p.m.

Last Modified :

Sept. 5, 2026, 9:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-67279 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Mikrotik routeros
2 Mikrotik routeros
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6
CVSS 4.0 MEDIUM [email protected]
Solution
Update RouterOS to a fixed version to resolve the unauthenticated session channel vulnerability.
  • Update RouterOS to version 6.49.21 or later.
  • Update RouterOS to version 7.23.4 or later.
  • Update RouterOS to version 7.24.2 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-67279 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-67279 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-67279 vulnerability anywhere in the article.

  • cert.pl
Vulnerabilities in Mikrotik RouterOS software

Vulnerabilities in Mikrotik RouterOS software CVE ID CVE-2026-67276 Publication date 05 September 2026 Vendor Mikrotik Product RouterOS Vulnerable versions From 7.24 below 7.24.2From 7.0.0 below 7.23. ... Read more

Published Date: Sep 05, 2026 (8 hours, 58 minutes ago)

The following table lists the changes that have been made to the CVE-2026-67279 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Sep. 05, 2026

    Action Type Old Value New Value
    Changed 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)
  • New CVE Received by [email protected]

    Sep. 05, 2026

    Action Type Old Value New Value
    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)
    Added CVSS V4.0 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
    Added CWE CWE-841
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/67xxx/CVE-2026-67279.json">CVE-2026-67279</a>
    Added Reference https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve
    Added Reference https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/
    Added Reference https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
    Added Reference https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
    Added Reference https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
    Added Reference https://mikrotik.com/supportsec/september-2026-vulnerability/
    Added Reference https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.