The US Cybersecurity and Infrastructure Security Agency (CISA) added CVE-2026-67279, a Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability, to its Known Exploited Vulnerabilities (KEV) catalog on September 25, 2026. CISA adds a flaw to the catalog when it has reliable evidence that attackers are exploiting it in the wild.
What CISA says
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.
— CISA KEV catalog entry for CVE-2026-67279
Key facts
| CVE | CVE-2026-67279 |
|---|---|
| Vendor / product | MikroTik RouterOS |
| Added to KEV | September 25, 2026 |
| Federal deadline | September 28, 2026 |
| Known ransomware use | Unknown |
| Weakness (CWE) | CWE-841 |
| CISA forensic triage | No |
| CVSS base score (NVD) | 6.9 Medium |
| CVSS vector | 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 |
Who has to act, and by when
US federal civilian executive branch agencies are required to remediate the vulnerability by September 28, 2026. CISA urges all organizations to prioritize KEV-listed flaws as part of their vulnerability management.
CISA’s required action for this entry:
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.
References
- CISA Known Exploited Vulnerabilities Catalog https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- NIST NVD — CVE-2026-67279 https://nvd.nist.gov/vuln/detail/CVE-2026-67279
- mikrotik.com https://mikrotik.com/supportsec/september-2026-vulnerability/?utm_source=chatgpt.com
- www.cisa.gov https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- www.cisa.gov https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk