CVE-2026-16347

HIGH

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

Title source: cna
STIX 2.1

Description

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.

References (1)

Core 1
Core References
Government Resource government-resource
https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05

Scores

CVSS v3 8.8
EPSS 0.0023
EPSS Percentile 14.4%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-307
Status published
Products (2)
MikroTik/Cloud Hosted Router All versions
MikroTik/RouterOS All versions
Published Jul 28, 2026
Tracked Since Jul 29, 2026