Medium severity · published Sep 5, 2026
CVE-2026-67279
SSH Pre-Authentication Rekey State Bypass in MikroTik RouterOS
In wildKEV
6.5
CVSS
2.3%
EPSS
Yes
On KEV
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)
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)2.3% · higher than 83% of CVEs
Exploited in the wildYes
CISA KEVListed Sep 25, 2026
Federal remediation dueSep 28, 2026
Ransomware campaign useNot known
Affected products
Which versions
RO
RouterOS · Mikrotik
7.24 before 7.24.2; 7.0.0 before 7.23.4; 6.0.0 before 6.49.21 · source: vendor, NVD, KEV
In the news
AdvisoryHigh
CISA Adds Two Known Exploited Vulnerabilities to Catalog
CISA has added two new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation. CVE-2026-65660 Microsoft SharePoint Code Injection Vulnerability CVE-2026-67279 Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability These types of vulnerabilities are a frequent attack vector for malicious cyber actors and pose significant risks to the federal enterprise.  Binding Operational Directive (BOD) 26-04: Prioritizing Security Updates Based on Risk establishes vulnerability management requirements for Federal Civilian Executive Branch (FCEB) agencies. BOD 26-04 reinforces the importance of the KEV Catalog and requires federal agencies to prioritize rapid remediation of high-risk vulnerabilities, specifically those identified by Common Vulnerabilities and Exposures (CVEs) listed in CISA’s KEV Catalog on publicly exposed assets that grant total control of the asset post-exploitation, while deferring action for lower-risk vulnerabilities. BOD 26-04 further establishes basic expectations for when agencies must check whether threat actors compromised the system before the patch was applied.  While BOD 26-04 applies only to FCEB agencies, CISA encourages all organizations to adopt risk-based vulnerability management and prioritize remediation of KEV Catalog vulnerabilities . CISA will continue to add vulnerabilities to the catalog that meet the specified criteria .  Aware of ...
Sep 25, 2026·CISA Advisories
VulnerabilityHigh
[CISA KEV] CVE-2026-67279: MikroTik RouterOS - Mikrotik RouterOS Improper Enforcement of Behavioral Workflow 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.
RORouterOSCVE-2026-67279
Sep 25, 2026·CISA KEV
VulnerabilityHigh
MikroTrick Chain Let Attackers Take Over MikroTik Routers Without a Password or SSH Key
Two MikroTik RouterOS SSH vulnerabilities chained together let attackers take full administrative control of Internet-exposed routers without a password, SSH key, or completed authentication. The chain, which CERT Polska calls MikroTrick, combines an SSH state-machine flaw (CVE-2026-67279) with an argument-injection bug in the RouterOS login process (CVE-2026-86060). Attack logs date to at
Sep 23, 2026·The Hacker News