{
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          "vendor": "ronf",
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          "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.1"
          }
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      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-639",
              "description": "CWE-639: Authorization Bypass Through User-Controlled Key",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-08T20:36:45.258Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/ronf/asyncssh/security/advisories/GHSA-qr67-gv47-xwwh",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/ronf/asyncssh/security/advisories/GHSA-qr67-gv47-xwwh"
        },
        {
          "name": "https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88",
          "tags": [
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          "url": "https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88"
        },
        {
          "name": "https://github.com/ronf/asyncssh/releases/tag/v2.23.1",
          "tags": [
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          "url": "https://github.com/ronf/asyncssh/releases/tag/v2.23.1"
        }
      ],
      "source": {
        "advisory": "GHSA-qr67-gv47-xwwh",
        "discovery": "UNKNOWN"
      },
      "title": "AsyncSSH AuthorizedKeysFile username substitution bypass through ~ and environment expansion"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-54590",
    "datePublished": "2026-07-08T20:36:45.258Z",
    "dateReserved": "2026-06-15T19:45:23.538Z",
    "dateUpdated": "2026-07-08T20:36:45.258Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-54590\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-08T21:16:49.523\",\"lastModified\":\"2026-07-08T21:16:49.523\",\"vulnStatus\":\"Received\",\"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.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"ronf\",\"product\":\"asyncssh\",\"versions\":[{\"version\":\"\u003c 2.23.1\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"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}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-22\"},{\"lang\":\"en\",\"value\":\"CWE-639\"}]}],\"references\":[{\"url\":\"https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/ronf/asyncssh/releases/tag/v2.23.1\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/ronf/asyncssh/security/advisories/GHSA-qr67-gv47-xwwh\",\"source\":\"security-advisories@github.com\"}]}}"
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}