CVE-2026-16347

Improper restriction of excessive authentication attempts in MikroTik RouterOS and Cloud Hosted Router

CVSS 8.7 high · MikroTik RouterOS · published 2026-07-28

MikroTik RouterOS contains a weakness in its API authentication handling that lacks effective safeguards against excessive login attempts. The system does not enforce meaningful rate-limiting, account lockout, or source-based restrictions, allowing repeated authentication failures to proceed without defensive response. In some versions, a fixed per-connection delay is present, but it can be bypassed through concurrent sessions, resulting in continued high-volume attempts. This deficiency increases the risk that an attacker could eventually obtain valid credentials and gain unauthorized access to administrative services.

NVD · CVE.org

Coverage 1 source

1. 2026-07-28 CISA Cybersecurity Advisories high MikroTik RouterOS and Cloud Hosted Router

   MikroTik RouterOS and Cloud Hosted Router have a vulnerability allowing rapid password guessing and unauthorized access.

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