{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.23.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2af2382cce946c959a378a62f257af253dc4ab51"
            },
            {
              "fixed": "3d515ba9ba0cd9990d248bdf62bcf05d51261a88"
            }
          ],
          "repo": "https://github.com/ronf/asyncssh",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-g794-3fmp-753h"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-22"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45309.json"
  },
  "details": "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.",
  "id": "CVE-2026-45309",
  "modified": "2026-07-19T03:30:50.821653276Z",
  "published": "2026-07-17T18:40:02.428Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45309.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/ronf/asyncssh/security/advisories/GHSA-g794-3fmp-753h"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45309"
    },
    {
      "type": "FIX",
      "url": "https://github.com/ronf/asyncssh/commit/2af2382cce946c959a378a62f257af253dc4ab51"
    },
    {
      "type": "FIX",
      "url": "https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "AsyncSSH `AuthorizedKeysFile %u` path traversal allows attacker-selected authorized keys to authenticate a traversal username"
}