Mikrotik RouterOS Improper Enforcement of Behavioral Workflow
CVE-2026-67279 is a medium-severity improper enforcement of behavioral workflow vulnerability in RouterOS from MikroTik, with a CVSS 3.1 base score of 6.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 7.24.2, 7.23.4, 6.49.21 as the first without the flaw, so updating RouterOS to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on September 25, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update RouterOS to 7.24.2 or 7.23.4 or 6.49.21, whichever matches your release line, or a later version.
- CISA's 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.
- Read the advisory on mikrotik.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Mikrotik | RouterOS | 7.24 up to, but not including, 7.24.2; 7.0.0 up to, but not including, 7.23.4; 6.0.0 up to, but not including, 6.49.21 | 7.24.2, 7.23.4, 6.49.21 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.9 | Medium | CNA (cert.pl) |
| CVSS 3.1 | 6.5 | Medium | NVD |
Official 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)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Enforcement of Behavioral Workflow
The product supports a session in which more than one behavior must be performed by an actor, but it does not properly ensure that the actor performs the behaviors in the required sequence or timeframe.
More Improper Enforcement of Behavioral Workflow vulnerabilities (CWE-841)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: partial).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Record last changed materially (score, affected products, status or references).
- Deadline for US federal agencies to remediate, set by CISA.
References
Patches and release notes
- cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/Mitigation, Third 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
Third-party and government advisories
- cert.pl/en/posts/2026/09/mikrotik-routeros-cveThird 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
Technical write-ups (may include proof of concept)
- npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/Exploit, Third Party Advisory
Our coverage
Other vulnerabilities in RouterOS
- 7.4 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
Recent Improper Enforcement of Behavioral Workflow vulnerabilities
- 8.7 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
- 7.5 High severity
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