Vulnerability-Lookup

GHSA-J9WG-77FW-F22F

Vulnerability from github – Published: 2026-09-05 21:31 – Updated: 2026-09-25 15:31

Details

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)

Severity

8.1 (High)


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

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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-67276"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-347"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-05T20:17:17Z",
    "severity": "CRITICAL"
  },
  "details": "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": "GHSA-j9wg-77fw-f22f",
  "modified": "2026-09-25T15:31:25Z",
  "published": "2026-09-05T21:31:19Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-67276"
    },
    {
      "type": "WEB",
      "url": "https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve"
    },
    {
      "type": "WEB",
      "url": "https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited"
    },
    {
      "type": "WEB",
      "url": "https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802"
    },
    {
      "type": "WEB",
      "url": "https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801"
    },
    {
      "type": "WEB",
      "url": "https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800"
    },
    {
      "type": "WEB",
      "url": "https://mikrotik.com/supportsec/september-2026-vulnerability"
    },
    {
      "type": "WEB",
      "url": "https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-67276 (GCVE-0-2026-67276)

Vulnerability from cvelistv5 – Published: 2026-09-05 20:00 – Updated: 2026-09-09 04:26

Title

SSH user impersonation possible in Mikrotik RouterOS

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

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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-08 00:00 UTC

CWE

CWE-347 - Improper verification of cryptographic signature

Assigner

CERT-PL CNA under the ENISA root

CNA scorecard B 81/100 over 219 records in the last 180 days details

References

6 references

URL	Tags
https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve	third-party-advisory
https://cert.pl/en/posts/2026/09/vulnerabilities-…	technical-description
https://npratley.net/reversing-mikrotiks-silent-p…	exploit
https://mikrotik.com/supportsec/september-2026-vu…	vendor-advisory
https://forum.mikrotik.com/t/7-23-4-long-term-is-…	release-notes
https://forum.mikrotik.com/t/7-24-2-stable-is-rel…	release-notes

Impacted products

1 product

Vendor	Product	Version
Mikrotik	RouterOS	Affected: 7.24 , < 7.24.2 (custom) Affected: 7.9 , < 7.23.4 (custom) cpe:2.3:a:mikrotik:routeros:::::::: cpe:2.3:a:mikrotik:routeros::::::::

Date Public

2026-09-05 00:00

Credits

Sławomir Rozbicki (CERT.PL)

Show details on NVD website

JSON

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                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-08T00:00:00+00:00",
                "version": "2.0.3"
              },
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        "providerMetadata": {
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
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          "vendor": "Mikrotik",
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              "status": "affected",
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            },
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              "lessThan": "7.23.4",
              "status": "affected",
              "version": "7.9",
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            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:a:mikrotik:routeros:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
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                  "versionEndExcluding": "7.23.4",
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                  "vulnerable": true
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        }
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            "subConfidentialityImpact": "NONE",
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            "vulnerabilityResponseEffort": "NOT_DEFINED"
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          "scenarios": [
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        "orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
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        },
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          "url": "https://mikrotik.com/supportsec/september-2026-vulnerability/"
        },
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          "url": "https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801"
        },
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          ],
          "url": "https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800"
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    "dateReserved": "2026-07-29T11:59:30.538Z",
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    "state": "PUBLISHED"
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}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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