{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-16347", "assignerOrgId": "7d14cffa-0d7d-4270-9dc0-52cabd5a23a6", "state": "PUBLISHED", "assignerShortName": "icscert", "dateReserved": "2026-07-20T20:41:22.596Z", "datePublished": "2026-07-28T19:59:29.927Z", "dateUpdated": "2026-07-28T19:59:29.927Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "7d14cffa-0d7d-4270-9dc0-52cabd5a23a6", "shortName": "icscert", "dateUpdated": "2026-07-28T19:59:29.927Z"}, "title": "Improper restriction of excessive authentication attempts in MikroTik RouterOS and Cloud Hosted Router", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-307", "description": "CWE-307 Improper restriction of excessive authentication attempts", "type": "CWE"}]}], "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"}], "descriptions": [{"lang": "en", "value": "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.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "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.&nbsp;<br>"}]}], "references": [{"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05", "tags": ["government-resource"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 8.8, "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "ADJACENT", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "HIGH", "baseScore": 8.7, "vectorString": "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"}}], "workarounds": [{"lang": "en", "value": "No fix is currently available from MikroTik. Until a fix is available, MikroTik recommends that users adopt the following mitigations: Use a strong VPN or other additional protection layer if the API is exposed to public networks.\n\n* Configure the unsuccessful-attempt time range (0.1 to 0.5 seconds) in /ip service for all services, including the API, once available.\n\n* Connect initially from a trusted network (LAN) port only, then configure the router per your security requirements.\n\n* Restrict/limit access to management services from untrusted networks.\n\n* Apply firewall rules to control and restrict access to management services where possible.\n\n* Use long, randomly generated passwords rather than weak or default-simple ones, to keep the brute-force search space impractically large.\n\n* Keep the default randomly generated device password, or replace it with an equally strong one, since minimum complexity isn't enforced by default.\n\n\n\nUsers are encouraged to reach out to MikroTik (https://mikrotik.com/support) for further support.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "No fix is currently available from MikroTik. Until a fix is available, MikroTik recommends that users adopt the following mitigations: Use a strong VPN or other additional protection layer if the API is exposed to public networks.\n<br>* Configure the unsuccessful-attempt time range (0.1 to 0.5 seconds) in /ip service for all services, including the API, once available.\n<br>* Connect initially from a trusted network (LAN) port only, then configure the router per your security requirements.\n<br>* Restrict/limit access to management services from untrusted networks.\n<br>* Apply firewall rules to control and restrict access to management services where possible.\n<br>* Use long, randomly generated passwords rather than weak or default-simple ones, to keep the brute-force search space impractically large.\n<br>* Keep the default randomly generated device password, or replace it with an equally strong one, since minimum complexity isn't enforced by default.\n<br>\n<br>Users are encouraged to reach out to MikroTik (https://mikrotik.com/support) for further support.&nbsp;"}]}], "credits": [{"lang": "en", "value": "Andre Santos of Uni\u00e3o Geek reported this vulnerability to CISA.", "type": "finder"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.4"}}}}

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