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Vulnerability record · CVE-2026-67279 · published 5 September 2026

CVE-2026-67279: Mikrotik routeros vulnerability

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)

6.9 CVSS 4.0 Medium CISA KEV since 25 Sep 2026 EPSS 1.0% · top 37.8% CWE-841 · CWE-841
6.9CVSS 4.0 base score
1.0%EPSS exploitation probability, 30 days
YesIn CISA KEV, federal fix due in 0 days
1Affected product versions listed by NVD
9References, 1 tagged exploit
26 Sep 2026Last modified by NVD

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)

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/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:

Exploitation in the wild

CISA added CVE-2026-67279 to the Known Exploited Vulnerabilities catalog on 25 September 2026 as "Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability". 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. Federal deadline 28 September 2026.

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve Third Party Advisory
https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ MitigationThird Party Advisory
https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802 Release Notes
https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 Release Notes
https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 Release Notes
https://mikrotik.com/supportsec/september-2026-vulnerability/ Vendor Advisory
https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ ExploitThird Party Advisory
https://bishopfox.com/blog/mikrotrick-inside-the-routeros-takeover-chain Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67279 US Government Resource

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-67279), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.