---
title: "CVE-2026-67279: Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-67279/
description: "CVE-2026-67279 (MikroTik RouterOS): Exploited in the wild (CISA KEV). RouterOS SSH enters the connection protocol after a client-requested rekey even though…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-05
date_modified: 2026-10-06
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-67279"
kev: true
cvss: 6.9
epss: 0.01027
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-67279: Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run MikroTik RouterOS. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-09-25, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-09-28 ; treat that as the outer limit, not the target.
- EPSS 1.0% , percentile 63: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 63% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Editorial verdict: Act now. MikroTrick: Exploited MikroTik RouterOS SSH Takeover Chain — If you run MikroTik routers, upgrade them now and check for an 'ops' admin account; an unauthenticated SSH chain to full admin was exploited a day before patches shipped.

## What it 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)

## Affected products (CVE record)

- Mikrotik RouterOS: 7.24 < 7.24.2, 7.0.0 < 7.23.4, 6.0.0 < 6.49.21

## Severity

- CERT-PL CVSS 4.0: 6.9 `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`

## Exploitation

- CISA KEV: added 2026-09-25; federal due date 2026-09-28. Known ransomware use: Unknown.
- CISA required action: 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.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 1.03% probability of exploitation activity in the next 30 days; percentile 63.

## Sources

- [mikrotik.com](https://mikrotik.com/supportsec/september-2026-vulnerability/)
- [forum.mikrotik.com](https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802)
- [forum.mikrotik.com](https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801)
- [forum.mikrotik.com](https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800)
- [CVE.org record CVE-2026-67279](https://www.cve.org/CVERecord?id=CVE-2026-67279)
- [NVD entry CVE-2026-67279](https://nvd.nist.gov/vuln/detail/CVE-2026-67279)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67279)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk)
- [cert.pl](https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve)
- [cert.pl](https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/)
- [npratley.net](https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/)
- [bishopfox.com](https://bishopfox.com/blog/mikrotrick-inside-the-routeros-takeover-chain)

---
Source page: https://erroneo.us/security/cve/CVE-2026-67279/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt