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FKIE_CVE-2026-67276

Vulnerability from fkie_nvd - Published: 2026-09-05 20:17 - Updated: 2026-09-05 21:16
Severity
9.2 (Critical) - CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Summary
RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)
References
cvd@cert.plhttps://cert.pl/en/posts/2026/09/mikrotik-routeros-cve
cvd@cert.plhttps://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/
cvd@cert.plhttps://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
cvd@cert.plhttps://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
cvd@cert.plhttps://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
cvd@cert.plhttps://mikrotik.com/supportsec/september-2026-vulnerability/
cvd@cert.plhttps://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "RouterOS",
          "vendor": "Mikrotik",
          "versions": [
            {
              "lessThan": "7.24.2",
              "status": "affected",
              "version": "7.24",
              "versionType": "custom"
            },
            {
              "lessThan": "7.23.4",
              "status": "affected",
              "version": "7.0.0",
              "versionType": "custom"
            },
            {
              "lessThan": "6.49.21",
              "status": "affected",
              "version": "6.0.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "cvd@cert.pl"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue was fixed in versions:\u00a06.49.21 (Long-term),\u00a07.23.4 (Long-term)\u00a0and\u00a07.24.2 (Stable)"
    }
  ],
  "id": "CVE-2026-67276",
  "lastModified": "2026-09-05T21:16:49.387",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "HIGH",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.2,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:H/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": "cvd@cert.pl",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-05T20:17:17.977",
  "references": [
    {
      "source": "cvd@cert.pl",
      "url": "https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve"
    },
    {
      "source": "cvd@cert.pl",
      "url": "https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/"
    },
    {
      "source": "cvd@cert.pl",
      "url": "https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802"
    },
    {
      "source": "cvd@cert.pl",
      "url": "https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801"
    },
    {
      "source": "cvd@cert.pl",
      "url": "https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800"
    },
    {
      "source": "cvd@cert.pl",
      "url": "https://mikrotik.com/supportsec/september-2026-vulnerability/"
    },
    {
      "source": "cvd@cert.pl",
      "url": "https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/"
    }
  ],
  "sourceIdentifier": "cvd@cert.pl",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-347"
        }
      ],
      "source": "cvd@cert.pl",
      "type": "Secondary"
    }
  ]
}



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