CVE-2026-16347CWE-307

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

High · published July 28, 2026

CVSS v4.0
8.7
EPSS
0%
Percentile
31.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.7 · HIGH
Vector
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
0.00388 · 31.7th percentile
Weakness
CWE-307 · Improper Restriction of Excessive Authentication Attempts
Published
2026-07-28T19:59Z
EPSS history
Timeline
  • 28 JUL 19:59Z
    Improper restriction of excessive authentication attempts in MikroTik RouterOS and Cloud Hosted Router
    cvelistv5