Vulnerability in Mikrotik Cloud Hosted Router

CVE-2026-16347

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.

EPSS: 0.003 (18.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-16347?
CVE-2026-16347 is a high-severity vulnerability in Mikrotik Cloud Hosted Router, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 8.8/10. Published 2026-07-28.
How severe is CVE-2026-16347?
High severity. CVSS v3 base score is 8.8 out of 10.