CVE-2026-67279: Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 25 Sep 2026, 20 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 2.3%
EPSS score, percentile 83.1 of all scored records
- How severe?
- 6.9 Medium
CVSS v4.0 base score, given by the CNA
- What should I do?
CISA deadline 28 Sep 2026. Apply mitigations in accordance with vendor instructions … Full text
- Which versions are affected?
Affected
- from 7.24 to before 7.24.2
- from 7.0.0 to before 7.23.4
- from 6.0.0 to before 6.49.21
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
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.
CISA due date for this action: 28 September 2026.
Advisories and patches
Linked from CISA's catalog entry
- https://mikrotik.com/supportsec/september-2026-vulnerability
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- https://nvd.nist.gov/vuln/detail/CVE-2026-67279
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 7.24 to before 7.24.2 |
| Affected | from 7.0.0 to before 7.23.4 |
| Affected | from 6.0.0 to before 6.49.21 |
Versions not listed are: unaffected.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
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.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2026-67279 to its Known Exploited Vulnerabilities (KEV) catalog on 25 Sep 2026.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 28 Sep 2026.
- The CVE record was published on 5 Sep 2026, 20 days before it was added to KEV.
- The CVE record carries a CVSS v4.0 base score of 6.9 (Medium), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 2.3% (percentile 83.1), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact partial.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
SSH Pre-Authentication Rekey State Bypass in 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)
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
- CWE-841: Improper enforcement of behavioral workflow
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 5 Sep 2026 | CVE record published |
| 25 Sep 2026 | Added to CISA KEV |
| 26 Sep 2026 | CVE record last updated |
| 28 Sep 2026 | CISA due date for the required action |
References
More exploited MikroTik vulnerabilities
- CVE-2026-67277: MikroTik RouterOS Missing Authentication for Critical Function Vulnerability
- CVE-2026-86060: MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command Vulnerability
- CVE-2018-7445: MikroTik RouterOS Stack-Based Buffer Overflow Vulnerability
- CVE-2018-14847: MikroTik Router OS Directory Traversal Vulnerability