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CVE-2026-67276

Status: AnalyzedCritical (9.2)—

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 affects only 7.x branch was fixed in versions: 7.23.4 (Long-term) and 7.24.2 (Stable)

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Mikrotik — Routeros

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-67276",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-67276",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-08T00:00:00+00:00"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.1,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.2
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "cvd@cert.pl",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 9.2,
          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "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",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "HIGH",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
        }
      }
    ]
  },
  "affected": [
    {
      "source": "cvd@cert.pl",
      "affectedData": [
        {
          "vendor": "Mikrotik",
          "product": "RouterOS",
          "versions": [
            {
              "status": "affected",
              "version": "7.24",
              "lessThan": "7.24.2",
              "versionType": "custom"
            },
            {
              "status": "affected",
              "version": "7.9",
              "lessThan": "7.23.4",
              "versionType": "custom"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
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  ],
  "published": "2026-09-05T20:17:17.977",
  "references": [
    {
      "url": "https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "cvd@cert.pl"
    },
    {
      "url": "https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/",
      "tags": [
        "Mitigation",
        "Third Party Advisory"
      ],
      "source": "cvd@cert.pl"
    },
    {
      "url": "https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801",
      "tags": [
        "Release Notes"
      ],
      "source": "cvd@cert.pl"
    },
    {
      "url": "https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800",
      "tags": [
        "Release Notes"
      ],
      "source": "cvd@cert.pl"
    },
    {
      "url": "https://mikrotik.com/supportsec/september-2026-vulnerability/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cvd@cert.pl"
    },
    {
      "url": "https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "source": "cvd@cert.pl"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "cvd@cert.pl",
      "description": [
        {
          "lang": "en",
          "value": "CWE-347"
        }
      ]
    }
  ],
  "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 affects only 7.x branch was fixed in versions: 7.23.4 (Long-term) and 7.24.2 (Stable)"
    }
  ],
  "lastModified": "2026-09-25T14:57:53.150",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "7B88D531-98F2-41B2-AC4F-0170D7DB15C2",
              "versionEndExcluding": "7.23.4",
              "versionStartIncluding": "7.9"
            },
            {
              "criteria": "cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A41D6B3C-D321-4C61-B3D5-00F8276CB4AC",
              "versionEndExcluding": "7.24.2",
              "versionStartIncluding": "7.24"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cvd@cert.pl"
}