Vulnerability-Lookup

GHSA-QC4P-9828-MV83

Vulnerability from github – Published: 2026-09-30 12:35 – Updated: 2026-09-30 12:35

Details

In Apache MINA SSHD versions up to 2.19.0 and 3.0.0-M1 to 3.0.0-M5 the server code in component sshd-core does not enforce that the two public keys presented are different. A user can thus successfully authenticate with only one of the two key pairs required by presenting this single key twice. This is a partial authentication bypass.

Users are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this issue.

Severity

8.1 (High)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-93994"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-304"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-30T10:17:17Z",
    "severity": "HIGH"
  },
  "details": "Apache MINA SSHD is a Java library for client-side and server-side SSH. SSH servers can be configured to require multi-authentication schemes, for instance two different public keys, not just one. In OpenSSH, this would be done by setting in sshd_config AuthenticationMethods \"publickey,publickey\". Apache MINA SSHD provides an equivalent configuration mechanism.\n\n\n\n\nIn Apache MINA SSHD versions up to 2.19.0 and 3.0.0-M1 to 3.0.0-M5 the server code in component sshd-core does not enforce that the two public keys presented are different. A user can thus successfully authenticate with only one of the two key pairs required by presenting this single key twice. This is a partial authentication bypass.\n\n\n\n\n\n\nUsers are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this issue.",
  "id": "GHSA-qc4p-9828-mv83",
  "modified": "2026-09-30T12:35:16Z",
  "published": "2026-09-30T12:35:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93994"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread.html/9t3vsm8rnvwdv9779mlg1lq2fbwojdwp"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/29/33"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-93994 (GCVE-0-2026-93994)

Vulnerability from cvelistv5 – Published: 2026-09-30 09:45 – Updated: 2026-09-30 14:29

Title

Apache MINA SSHD: Repeated-publickey policy bypass on server

Summary

Apache MINA SSHD is a Java library for client-side and server-side SSH. SSH servers can be configured to require multi-authentication schemes, for instance two different public keys, not just one. In OpenSSH, this would be done by setting in sshd_config AuthenticationMethods "publickey,publickey". Apache MINA SSHD provides an equivalent configuration mechanism. In Apache MINA SSHD versions up to 2.19.0 and 3.0.0-M1 to 3.0.0-M5 the server code in component sshd-core does not enforce that the two public keys presented are different. A user can thus successfully authenticate with only one of the two key pairs required by presenting this single key twice. This is a partial authentication bypass. Users are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this issue.

Severity

8.1 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-30 14:29 UTC

CWE

CWE-304 - Missing critical step in authentication

Assigner

apache mitre root Scorecard

References

2 references

URL	Tags
https://lists.apache.org/thread.html/9t3vsm8rnvwd…	vendor-advisory
http://www.openwall.com/lists/oss-security/2026/0…

Impacted products

1 product

Vendor	Product	Version
Apache Software Foundation	Apache MINA SSHD	Affected: 0 , < 2.20.0 (maven) Affected: 3.0.0-M1 , < 3.0.0-M6 (maven)

Credits

Abhishek Kushwaha

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

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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.
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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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-QC4P-9828-MV83

CVE-2026-93994 (GCVE-0-2026-93994)

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