CVE-2026-67279
Mikrotik RouterOS contains an improper enforcement of behavioral workflow vulnerability that could allow an unauthenticated client to open a session channel and send an exec request. This vulnerability can be chained to achieve unauthenticated exploitation of CVE-2026-86060.
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:X/V:X/RE:X/U:X- cert.pl/en/posts/2026/09/mikrotik-routeros-cveThird Party Advisory
- cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/MitigationThird Party Advisory
- forum.mikrotik.com/t/6-49-21-long-term-is-released/272802Release Notes
- forum.mikrotik.com/t/7-23-4-long-term-is-released/272801Release Notes
- forum.mikrotik.com/t/7-24-2-stable-is-released/272800Release Notes
- mikrotik.com/supportsec/september-2026-vulnerability/Vendor Advisory
- npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ExploitThird Party Advisory
- bishopfox.com/blog/mikrotrick-inside-the-routeros-takeover-chainThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67279US Government Resource
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 29 days
- CVSS
- 6.9 MEDIUM
- EPSS (30-day exploit probability)
- 2.3% · top 17% of all CVEs
- Weakness
- CWE-841
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
- 1.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.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.