CVE-2026-67279
Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability
IN CISA KEV
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)
- Vendor
- MikroTik
- Product
- RouterOS
- CVSS 3.1
- 6.5 (medium), scored by NVD (primary)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- CVSS 4.0
- 6.9 (medium), scored by cvd@cert.plCVSS: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:X/V:X/RE:X/U:X
- CWE
- CWE-841
- Published
- 2026-09-05
- NVD modified
- 2026-09-26
- NVD status
- Analyzed
CISA KEV
- Date added
- 2026-09-25
- Due date
- 2026-09-28
- Ransomware use
- Unknown
- 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.
EPSS
1.03% chance of exploitation in the next 30 days (percentile 63rd)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
References
- cert.pl (Third Party Advisory)
- cert.pl (Mitigation, Third Party Advisory)
- forum.mikrotik.com (Release Notes)
- forum.mikrotik.com (Release Notes)
- forum.mikrotik.com (Release Notes)
- mikrotik.com (Vendor Advisory)
- bishopfox.com (Third Party Advisory)
- www.cisa.gov (US Government Resource)
Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.