CVE-2026-16347: Brute Force (CVSS 8.8)

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.

Is your site exposed to CVE-2026-16347?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0023

Probability of exploitation

0.14%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-307 CWE-307

References

Other References

https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-16347? +

CVE-2026-16347 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0023, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-16347? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-2911

Unauthorised access to the call forwarding service system in MeetMe products in versions prior to 2024-09 allows an attacker to …

CVE-2025-24806

Authelia is an open-source authentication and authorization server providing two-factor authentication and single sign-on (SSO) for applications via a web …

CVE-2025-1714

Lack of Rate Limiting in Sign-up workflow in Perforce Gliffy prior to version 4.14.0-7 on Gliffy online allows attacker to …

CVE-2025-0417

Lack of protection against brute force attacks in Valmet DNA visualization in DNA Operate. The possibility to make an arbitrary …

CVE-2025-42600

This vulnerability exists in Meon KYC solutions due to missing restrictions on the number of incorrect One-Time Password (OTP) attempts …

CVE-2025-6029

Use of fixed learning codes, one code to lock the car and the other code to unlock it, the Key …

CVE-2026-16347