8.8
HIGH CVSS 3.1
CVE-2026-16347
Improper restriction of excessive authentication attempts in MikroTik RouterOS and Cloud Hosted Router
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.

INFO

Published Date :

July 28, 2026, 8:17 p.m.

Last Modified :

July 28, 2026, 8:17 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-16347 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Mikrotik routeros
2 Mikrotik routeros
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 7d14cffa-0d7d-4270-9dc0-52cabd5a23a6
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH MITRE-CVE
CVSS 4.0 HIGH 7d14cffa-0d7d-4270-9dc0-52cabd5a23a6
CVSS 4.0 HIGH [email protected]
Solution
Implement strong authentication controls to prevent brute-force attacks.
  • Apply security updates to RouterOS.
  • Configure robust rate limiting.
  • Enforce account lockout policies.
  • Implement source IP restrictions.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-16347.

URL Resource
https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-16347 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-16347 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-16347 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 28, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'MikroTik', 'product': 'RouterOS', 'versions': [{'status': 'affected', 'version': 'All versions'}], 'defaultStatus': 'affected'}, {'vendor': 'MikroTik', 'product': 'Cloud Hosted Router', 'versions': [{'status': 'affected', 'version': 'All versions'}], 'defaultStatus': 'affected'}]
    Added 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.
    Added CVSS V4.0 AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-307
    Added Reference https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.