Vulnerability-Lookup

CVE-2026-16347 (GCVE-0-2026-16347)

Vulnerability from cvelistv5 – Published: 2026-07-28 19:59 – Updated: 2026-07-29 13:57

Title

Improper restriction of excessive authentication attempts in MikroTik RouterOS and Cloud Hosted Router

Summary

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.

Severity

8.8 (High)


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

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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-307 - Improper restriction of excessive authentication attempts

Assigner

icscert

References

1 reference

URL	Tags
https://www.cisa.gov/news-events/ics-advisories/i…	government-resource

Impacted products

2 products

Vendor	Product	Version
MikroTik	RouterOS	Affected: All versions
MikroTik	Cloud Hosted Router	Affected: All versions

Credits

Andre Santos of União Geek reported this vulnerability to CISA.

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-16347

Vulnerability from fkie_nvd - Published: 2026-07-28 20:17 - Updated: 2026-07-28 20:17

Severity

8.8 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

References

	URL	Tags
	ics-cert@hq.dhs.gov	https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "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/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "ics-cert@hq.dhs.gov",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-28T20:17:23.713",
  "references": [
    {
      "source": "ics-cert@hq.dhs.gov",
      "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05"
    }
  ],
  "sourceIdentifier": "ics-cert@hq.dhs.gov",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-307"
        }
      ],
      "source": "ics-cert@hq.dhs.gov",
      "type": "Primary"
    }
  ]
}

GHSA-8V62-P5RJ-72X6

Vulnerability from github – Published: 2026-07-28 21:31 – Updated: 2026-07-28 21:31

Details

Severity

8.8 (High)


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

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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-16347"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-307"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-28T20:17:23Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-8v62-p5rj-72x6",
  "modified": "2026-07-28T21:31:33Z",
  "published": "2026-07-28T21:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-16347"
    },
    {
      "type": "WEB",
      "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "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/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",
      "type": "CVSS_V4"
    }
  ]
}

ICSA-26-209-05

Vulnerability from csaf_cisa - Published: 2026-07-28 06:00 - Updated: 2026-07-28 06:00

Summary

MikroTik RouterOS and Cloud Hosted Router

Notes

Legal Notice and Terms of Use: This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).

Advisory Summary: Successful exploitation of this vulnerability could allow attackers to rapidly guess passwords and gain unauthorized system access.

Critical infrastructure sectors: Information Technology, Commercial Facilities

Countries/areas deployed: Worldwide

Company headquarters location: Latvia

Recommended Practices: CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.

Recommended Practices: Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.

Recommended Practices: CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

Recommended Practices: CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Recommended Practices: CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.

Recommended Practices: Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Recommended Practices: Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.

Recommended Practices: No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability is not exploitable remotely.

CVE-2026-16347

8.8 (High)


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

CWE-307 - Improper Restriction of Excessive Authentication Attempts

Affected products

Known affected 2 products

Product	Identifier	Version	Remediation
MikroTik RouterOS: vers:all/* MikroTik / RouterOS		vers:all/*	Mitigation Mitigation Mitigation Mitigation Mitigation Mitigation Mitigation Mitigation fix
MikroTik Cloud Hosted Router: vers:all/* MikroTik / Cloud Hosted Router		vers:all/*	Mitigation Mitigation Mitigation Mitigation Mitigation Mitigation Mitigation Mitigation fix

References

15 references

URL	Category
https://raw.githubusercontent.com/cisagov/CSAF/de…	self
https://www.cisa.gov/news-events/ics-advisories/i…	self
https://www.cisa.gov/uscert/ics/alerts/ICS-ALERT-…	external
https://www.cisa.gov/resources-tools/resources/ic…	external
https://www.cisa.gov/sites/default/files/publicat…	external
https://www.cisa.gov/topics/industrial-control-systems	external
https://www.cisa.gov/news-events/ics-alerts/ics-a…	external
https://www.cisa.gov/sites/default/files/recommen…	external
https://www.cisa.gov/news-events/news/targeted-cy…	external
https://www.cisa.gov/secure-our-world/teach-emplo…	external
https://www.cisa.gov/news-events/news/avoiding-so…	external
https://cwe.mitre.org/data/definitions/307.html	external
https://www.cve.org/CVERecord?id=CVE-2026-16347	external
https://www.first.org/cvss/calculator/3.1#CVSS:3.…	external
https://www.first.org/cvss/calculator/4.0#CVSS:4.…	external

Acknowledgments

União Geek Andre Santos

JSON

To clipboard

{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "Andre Santos"
        ],
        "organization": "Uni\u00e3o Geek",
        "summary": "reported this vulnerability to CISA"
      }
    ],
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Disclosure is not limited",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.cisa.gov/news-events/news/traffic-light-protocol-tlp-definitions-and-usage"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy \u0026 Use policy (https://www.cisa.gov/privacy-policy).",
        "title": "Legal Notice and Terms of Use"
      },
      {
        "category": "summary",
        "text": "Successful exploitation of this vulnerability could allow attackers to rapidly guess passwords and gain unauthorized system access.",
        "title": "Advisory Summary"
      },
      {
        "category": "other",
        "text": "Information Technology, Commercial Facilities",
        "title": "Critical infrastructure sectors"
      },
      {
        "category": "other",
        "text": "Worldwide",
        "title": "Countries/areas deployed"
      },
      {
        "category": "other",
        "text": "Latvia",
        "title": "Company headquarters location"
      },
      {
        "category": "general",
        "text": "CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.",
        "title": "Recommended Practices"
      },
      {
        "category": "general",
        "text": "No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability is not exploitable remotely.",
        "title": "Recommended Practices"
      }
    ],
    "publisher": {
      "category": "coordinator",
      "contact_details": "central@cisa.dhs.gov",
      "name": "CISA",
      "namespace": "https://www.cisa.gov/"
    },
    "references": [
      {
        "category": "self",
        "summary": "ICS Advisory ICSA-26-209-05 JSON",
        "url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-209-05.json"
      },
      {
        "category": "self",
        "summary": "ICSA Advisory ICSA-26-209-05 - Web Version",
        "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-209-05"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/resources-tools/resources/ics-recommended-practices"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/sites/default/files/publications/Cybersecurity_Best_Practices_for_Industrial_Control_Systems.pdf"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/topics/industrial-control-systems"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/news-events/ics-alerts/ics-alert-10-301-01"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/news-events/news/targeted-cyber-intrusion-detection-and-mitigation-strategies-update-b"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/secure-our-world/teach-employees-avoid-phishing"
      },
      {
        "category": "external",
        "summary": "Recommended Practices",
        "url": "https://www.cisa.gov/news-events/news/avoiding-social-engineering-and-phishing-attacks"
      }
    ],
    "title": "MikroTik RouterOS and Cloud Hosted Router",
    "tracking": {
      "current_release_date": "2026-07-28T06:00:00.000000Z",
      "generator": {
        "date": "2026-07-27T16:54:30.691227Z",
        "engine": {
          "name": "CISA CSAF Generator",
          "version": "1.0.0"
        }
      },
      "id": "ICSA-26-209-05",
      "initial_release_date": "2026-07-28T06:00:00.000000Z",
      "revision_history": [
        {
          "date": "2026-07-28T06:00:00.000000Z",
          "legacy_version": "Initial",
          "number": "1",
          "summary": "Initial Publication"
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "vers:all/*",
                "product": {
                  "name": "MikroTik RouterOS: vers:all/*",
                  "product_id": "CSAFPID-0001"
                }
              }
            ],
            "category": "product_name",
            "name": "RouterOS"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "vers:all/*",
                "product": {
                  "name": "MikroTik Cloud Hosted Router: vers:all/*",
                  "product_id": "CSAFPID-0002"
                }
              }
            ],
            "category": "product_name",
            "name": "Cloud Hosted Router"
          }
        ],
        "category": "vendor",
        "name": "MikroTik"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-16347",
      "cwe": {
        "id": "CWE-307",
        "name": "Improper Restriction of Excessive Authentication Attempts"
      },
      "notes": [
        {
          "category": "summary",
          "text": "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.",
          "title": "Vulnerability Summary"
        },
        {
          "category": "details",
          "text": "SSVCv2/E:N/A:N/2026-07-27T06:00:00.000000Z",
          "title": "SSVC"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-0001",
          "CSAFPID-0002"
        ]
      },
      "references": [
        {
          "category": "external",
          "summary": "cwe.mitre.org",
          "url": "https://cwe.mitre.org/data/definitions/307.html"
        },
        {
          "category": "external",
          "summary": "www.cve.org",
          "url": "https://www.cve.org/CVERecord?id=CVE-2026-16347"
        },
        {
          "category": "external",
          "summary": "www.first.org",
          "url": "https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        },
        {
          "category": "external",
          "summary": "www.first.org",
          "url": "https://www.first.org/cvss/calculator/4.0#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"
        }
      ],
      "remediations": [
        {
          "category": "mitigation",
          "details": "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.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "Configure the unsuccessful-attempt time range (0.1 to 0.5 seconds) in /ip service for all services, including the API, once available.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "Connect initially from a trusted network (LAN) port only, then configure the router per your security requirements.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "Restrict/limit access to management services from untrusted networks.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "Apply firewall rules to control and restrict access to management services where possible.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "Use long, randomly generated passwords rather than weak or default-simple ones, to keep the brute-force search space impractically large.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "Keep the default randomly generated device password, or replace it with an equally strong one, since minimum complexity isn\u0027t enforced by default.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        },
        {
          "category": "mitigation",
          "details": "Users are encouraged to reach out to MikroTik (https://mikrotik.com/support) for further support.",
          "product_ids": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ],
          "url": "https://mikrotik.com/support"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-0001",
            "CSAFPID-0002"
          ]
        }
      ]
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-16347 (GCVE-0-2026-16347)

FKIE_CVE-2026-16347

GHSA-8V62-P5RJ-72X6

ICSA-26-209-05

Tags

Sightings

Nomenclature