MikroTik RouterOS/Cloud Hosted Router excessive authentication

Summaryinfo

A vulnerability classified as problematic has been found in MikroTik RouterOS and Cloud Hosted Router. This vulnerability affects unknown code. Performing a manipulation results in excessive authentication. This vulnerability is identified as CVE-2026-16347. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in MikroTik RouterOS and Cloud Hosted Router (version now known). It has been classified as problematic. This affects some unknown processing. The manipulation with an unknown input leads to a excessive authentication vulnerability. CWE is classifying the issue as CWE-307. The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame, making it more susceptible to brute force attacks. This is going to have an impact on confidentiality. The summary by CVE 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.

It is possible to read the advisory at cisa.gov. This vulnerability is uniquely identified as CVE-2026-16347 since 07/20/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/28/2026). The attack technique deployed by this issue is T1110.001 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Router Operating System

Vendor

• MikroTik

Name

• Cloud Hosted Router
• RouterOS

License

• commercial

CPE 2.3info

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CPE 2.2info

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