CVE-2026-16347
Improper restriction of excessive authentication attempts in MikroTik RouterOS and Cloud Hosted Router
- State
- Published
- Severity
- 8.7 High
- Published
- Jul 28, 2026
- Updated
- Jul 29, 2026
- Reserved
- Jul 20, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | 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 | icscert |
| 3.1 | 8.8 High | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | icscert |
Weaknesses
- CWE-307 Improper restriction of excessive authentication attempts
Affected Products
| Product | Versions |
|---|---|
RouterOSMikroTik |
|
Cloud Hosted RouterMikroTik |
|
References
- https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05government-resource
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