Vulnerability-Lookup

FKIE_CVE-2026-42189

Vulnerability from fkie_nvd - Published: 2026-05-08 20:16 - Updated: 2026-06-17 10:47

Severity

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

Summary

Russh is a Rust SSH client & server library. Prior to version 0.60.1, a pre-authentication denial-of-service vulnerability exists in the server's keyboard-interactive authentication handler. A malicious client can crash any russh-based server that implements keyboard-interactive auth (e.g., for 2FA/TOTP) with a single malformed packet, requiring no credentials. This issue has been patched in version 0.60.1.

References

URL	Tags
security-advisories@github.com	https://github.com/Eugeny/russh/commit/6c3c80a9b6d60763d6227d60fa8310e57172a4d1	Patch
security-advisories@github.com	https://github.com/Eugeny/russh/releases/tag/v0.60.1	Product, Release Notes
security-advisories@github.com	https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg	Exploit, Mitigation, Vendor Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg	Exploit, Mitigation, Vendor Advisory

Impacted products

	Vendor	Product	Version
	russh_project	russh	*
	warpgate_project	warpgate	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "russh",
          "vendor": "Eugeny",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.60.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:russh_project:russh:*:*:*:*:*:rust:*:*",
              "matchCriteriaId": "3B0C52D5-1F74-4959-9248-8CCE6309162E",
              "versionEndExcluding": "0.60.1",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:warpgate_project:warpgate:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "449C9C44-332F-4C2C-A619-33C5025249DB",
              "versionEndExcluding": "0.23.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Russh is a Rust SSH client \u0026 server library. Prior to version 0.60.1, a pre-authentication denial-of-service vulnerability exists in the server\u0027s keyboard-interactive authentication handler. A malicious client can crash any russh-based server that implements keyboard-interactive auth (e.g., for 2FA/TOTP) with a single malformed packet, requiring no credentials. This issue has been patched in version 0.60.1."
    }
  ],
  "id": "CVE-2026-42189",
  "lastModified": "2026-06-17T10:47:29.173",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-42189",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-11T14:23:22.063007Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-08T20:16:31.443",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/Eugeny/russh/commit/6c3c80a9b6d60763d6227d60fa8310e57172a4d1"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Product",
        "Release Notes"
      ],
      "url": "https://github.com/Eugeny/russh/releases/tag/v0.60.1"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        },
        {
          "lang": "en",
          "value": "CWE-789"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

CVE-2026-42189 (GCVE-0-2026-42189)

Vulnerability from cvelistv5 – Published: 2026-05-08 19:49 – Updated: 2026-05-11 14:23

Title

Russh: Pre-auth DoS via unbounded allocation in keyboard-interactive auth

Summary

Severity

7.5 (High)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-11 14:23 UTC

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling
CWE-789 - Memory Allocation with Excessive Size Value

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/Eugeny/russh/security/advisori…	x_refsource_CONFIRM
https://github.com/Eugeny/russh/commit/6c3c80a9b6…	x_refsource_MISC
https://github.com/Eugeny/russh/releases/tag/v0.60.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
Eugeny	russh	Affected: < 0.60.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-42189",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-11T14:23:22.063007Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-11T14:23:49.308Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "russh",
          "vendor": "Eugeny",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.60.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Russh is a Rust SSH client \u0026 server library. Prior to version 0.60.1, a pre-authentication denial-of-service vulnerability exists in the server\u0027s keyboard-interactive authentication handler. A malicious client can crash any russh-based server that implements keyboard-interactive auth (e.g., for 2FA/TOTP) with a single malformed packet, requiring no credentials. This issue has been patched in version 0.60.1."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-789",
              "description": "CWE-789: Memory Allocation with Excessive Size Value",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-08T19:49:51.179Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg"
        },
        {
          "name": "https://github.com/Eugeny/russh/commit/6c3c80a9b6d60763d6227d60fa8310e57172a4d1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/Eugeny/russh/commit/6c3c80a9b6d60763d6227d60fa8310e57172a4d1"
        },
        {
          "name": "https://github.com/Eugeny/russh/releases/tag/v0.60.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/Eugeny/russh/releases/tag/v0.60.1"
        }
      ],
      "source": {
        "advisory": "GHSA-f5v4-2wr6-hqmg",
        "discovery": "UNKNOWN"
      },
      "title": "Russh: Pre-auth DoS via unbounded allocation in keyboard-interactive auth"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-42189",
    "datePublished": "2026-05-08T19:49:51.179Z",
    "dateReserved": "2026-04-25T01:53:21.583Z",
    "dateUpdated": "2026-05-11T14:23:49.308Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.