CVE-2026-45309 (GCVE-0-2026-45309)

Vulnerability from cvelistv5 – Published: 2026-07-17 18:40 – Updated: 2026-07-17 18:40
VLAI
Title
AsyncSSH `AuthorizedKeysFile %u` path traversal allows attacker-selected authorized keys to authenticate a traversal username
Summary
AsyncSSH is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python asyncio framework. Prior to 2.23.0, AsyncSSH expands the OpenSSH-compatible AuthorizedKeysFile %u token in asyncssh/config.py, asyncssh/connection.py, asyncssh/auth_keys.py, and asyncssh/misc.py with the raw SSH username during pre-authentication server config reload, allowing a server configured with AuthorizedKeysFile authorized_keys/%u to read an authorized-keys file outside the intended directory when the SSH username contains /, \, or .. path traversal segments and authenticate with an attacker-selected key file. This issue is fixed in version 2.23.0.
Severity
8.2 (High)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CWE
  • CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
Impacted products
Vendor Product Version
ronf asyncssh Affected: < 2.23.0
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            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
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            "vulnIntegrityImpact": "HIGH"
          }
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              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-17T18:40:02.428Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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          "url": "https://github.com/ronf/asyncssh/commit/2af2382cce946c959a378a62f257af253dc4ab51"
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          "tags": [
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          "url": "https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88"
        }
      ],
      "source": {
        "advisory": "GHSA-g794-3fmp-753h",
        "discovery": "UNKNOWN"
      },
      "title": "AsyncSSH `AuthorizedKeysFile %u` path traversal allows attacker-selected authorized keys to authenticate a traversal username"
    }
  },
  "cveMetadata": {
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    "cveId": "CVE-2026-45309",
    "datePublished": "2026-07-17T18:40:02.428Z",
    "dateReserved": "2026-05-11T20:14:43.203Z",
    "dateUpdated": "2026-07-17T18:40:02.428Z",
    "state": "PUBLISHED"
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  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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