CVE-2026-54590

{
  "id": "CVE-2026-54590",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-08T21:16:49.523",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "AsyncSSH is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python asyncio framework. Version 2.23.0 contains an incomplete fix for CVE-2026-45309 in SSHServerConfig._set_tokens that blocks /, , and .. before %u substitution in AuthorizedKeysFile but does not block a leading ~ or ${ENV}, allowing later expansion in _expand_val and Path(filename).expanduser() to escape the intended authorized-keys directory. This issue is fixed in version 2.23.1."
    },
    {
      "lang": "es",
      "value": "AsyncSSH es un paquete de Python que proporciona una implementación asíncrona de cliente y servidor del protocolo SSHv2 sobre el framework asyncio de Python. La versión 2.23.0 contiene una corrección incompleta para CVE-2026-45309 en SSHServerConfig._set_tokens que bloquea /, \\, y .. antes de la sustitución de %u en AuthorizedKeysFile pero no bloquea un ~ inicial o ${ENV}, permitiendo una expansión posterior en _expand_val y Path(filename).expanduser() para escapar del directorio de claves autorizadas previsto. Este problema está corregido en la versión 2.23.1."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "ronf",
          "product": "asyncssh",
          "versions": [
            {
              "version": "< 2.23.1",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-10T15:00:13.292812Z",
          "id": "CVE-2026-54590",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        },
        {
          "lang": "en",
          "value": "CWE-639"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/ronf/asyncssh/releases/tag/v2.23.1",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/ronf/asyncssh/security/advisories/GHSA-qr67-gv47-xwwh",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/ronf/asyncssh/security/advisories/GHSA-qr67-gv47-xwwh",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}