CVE-2026-91166 (GCVE-0-2026-91166)

Vulnerability from cvelistv5 – Published: 2026-09-21 18:53 – Updated: 2026-09-21 18:53
VLAI
Title
Warpgate: Web SSH stores a jump host's key against the target's address, so it validates as the target
Summary
Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. From 0.25.0 until 0.27.6, the browser SSH path in warpgate-web-ssh/src/manager.rs handles RCEvent::HostKeyUnknown without the presenting hop identity and instead passes ssh_options.host and ssh_options.port for the final target to KnownHosts::trust. In Prompt and AutoAccept modes, a jump host key can therefore be stored for the target address. A machine later presenting the jump host key at the target address can be accepted as the target, allowing interception of user traffic and a newly issued certificate when certificate authentication is used. The native SSH path is unaffected because it tracks each hop separately. This issue is fixed in version 0.27.6.
Severity
5.7 (Medium)
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N
CWE
  • CWE-297 - Improper Validation of Certificate with Host Mismatch
  • CWE-923 - Improper Restriction of Communication Channel to Intended Endpoints
Assigner
References
Impacted products
Vendor Product Version CPE status
warp-tech warpgate Affected: >= 0.25.0, < 0.27.6
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "warpgate",
          "vendor": "warp-tech",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.25.0, \u003c 0.27.6"
            }
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        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. From 0.25.0 until 0.27.6, the browser SSH path in warpgate-web-ssh/src/manager.rs handles RCEvent::HostKeyUnknown without the presenting hop identity and instead passes ssh_options.host and ssh_options.port for the final target to KnownHosts::trust. In Prompt and AutoAccept modes, a jump host key can therefore be stored for the target address. A machine later presenting the jump host key at the target address can be accepted as the target, allowing interception of user traffic and a newly issued certificate when certificate authentication is used. The native SSH path is unaffected because it tracks each hop separately. This issue is fixed in version 0.27.6."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.7,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "HIGH",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-297",
              "description": "CWE-297: Improper Validation of Certificate with Host Mismatch",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-923",
              "description": "CWE-923: Improper Restriction of Communication Channel to Intended Endpoints",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-21T18:53:56.224Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/warp-tech/warpgate/security/advisories/GHSA-w9jj-vpw3-5r8f",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/warp-tech/warpgate/security/advisories/GHSA-w9jj-vpw3-5r8f"
        },
        {
          "name": "https://github.com/warp-tech/warpgate/commit/fb66ff74f979c22054f4d348cc0d9065cc67e5d3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/warp-tech/warpgate/commit/fb66ff74f979c22054f4d348cc0d9065cc67e5d3"
        },
        {
          "name": "https://github.com/warp-tech/warpgate/releases/tag/v0.27.6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/warp-tech/warpgate/releases/tag/v0.27.6"
        }
      ],
      "source": {
        "advisory": "GHSA-w9jj-vpw3-5r8f",
        "discovery": "UNKNOWN"
      },
      "title": "Warpgate: Web SSH stores a jump host\u0027s key against the target\u0027s address, so it validates as the target"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-91166",
    "datePublished": "2026-09-21T18:53:56.224Z",
    "dateReserved": "2026-09-14T21:20:41.196Z",
    "dateUpdated": "2026-09-21T18:53:56.224Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "warpgate",
                "vendor": "warp-tech",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003e= 0.25.0, \u003c 0.27.6"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. From 0.25.0 until 0.27.6, the browser SSH path in warpgate-web-ssh/src/manager.rs handles RCEvent::HostKeyUnknown without the presenting hop identity and instead passes ssh_options.host and ssh_options.port for the final target to KnownHosts::trust. In Prompt and AutoAccept modes, a jump host key can therefore be stored for the target address. A machine later presenting the jump host key at the target address can be accepted as the target, allowing interception of user traffic and a newly issued certificate when certificate authentication is used. The native SSH path is unaffected because it tracks each hop separately. This issue is fixed in version 0.27.6."
          }
        ],
        "id": "CVE-2026-91166",
        "lastModified": "2026-09-21T19:17:15.383",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 5.7,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "HIGH",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 0.5,
              "impactScore": 5.2,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-09-21T19:17:15.383",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/warp-tech/warpgate/commit/fb66ff74f979c22054f4d348cc0d9065cc67e5d3"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/warp-tech/warpgate/releases/tag/v0.27.6"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/warp-tech/warpgate/security/advisories/GHSA-w9jj-vpw3-5r8f"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Received",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-297"
              },
              {
                "lang": "en",
                "value": "CWE-923"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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