CVE-2026-67279: Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability

Medium severity, CVSS 6.5. Actively exploited: in CISA KEV since 2026-09-25. EPSS: 1% chance of exploitation in the next 30 days.

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)

Affected products

• MikroTik RouterOS: from 6.0, before 6.49.21 (fixed in 6.49.21); from 7.0, before 7.23.4 (fixed in 7.23.4); from 7.24, before 7.24.2 (fixed in 7.24.2)

Published 2026-09-05. Last modified 2026-09-26.