Vulnerability in Mikrotik Routeros
CVE-2026-67279
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)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.010 (63.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.010 · change: +0.006
Affected products
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
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.
Public proof-of-concept exploits
References
- cert.pl/en/posts/2026/09/mikrotik-routeros-cve (Third Party Advisory, third-party-advisory)
- cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploite… (technical-description, Third Party Advisory, Mitigation)
- forum.mikrotik.com/t/6-49-21-long-term-is-released/272802 (release-notes, Release Notes)
- forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 (release-notes, Release Notes)
- forum.mikrotik.com/t/7-24-2-stable-is-released/272800 (release-notes, Release Notes)
- mikrotik.com/supportsec/september-2026-vulnerability/ (vendor-advisory, Vendor Advisory)
- npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-woul… (Exploit, Third Party Advisory, exploit)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2026-67279?
- CVE-2026-67279 is a medium-severity vulnerability in Mikrotik Routeros, classified under Improper Enforcement of Behavioral Workflow. CVSS score: 6.5/10. Published 2026-09-05.
- How severe is CVE-2026-67279?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2026-67279 known to be exploited?
- Yes. CVE-2026-67279 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-09-25), indicating it is being actively exploited. 4 public proof-of-concept repositories are indexed.