{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-54590","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-15T19:45:23.538Z","datePublished":"2026-07-08T20:36:45.258Z","dateUpdated":"2026-07-10T15:00:21.849Z"},"containers":{"cna":{"title":"AsyncSSH AuthorizedKeysFile username substitution bypass through ~ and environment expansion","problemTypes":[{"descriptions":[{"cweId":"CWE-22","lang":"en","description":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-639","lang":"en","description":"CWE-639: Authorization Bypass Through User-Controlled Key","type":"CWE"}]}],"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"}}],"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":["x_refsource_MISC"],"url":"https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88"},{"name":"https://github.com/ronf/asyncssh/releases/tag/v2.23.1","tags":["x_refsource_MISC"],"url":"https://github.com/ronf/asyncssh/releases/tag/v2.23.1"}],"affected":[{"vendor":"ronf","product":"asyncssh","versions":[{"version":"< 2.23.1","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-07-08T20:36:45.258Z"},"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."}],"source":{"advisory":"GHSA-qr67-gv47-xwwh","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/ronf/asyncssh/security/advisories/GHSA-qr67-gv47-xwwh","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-10T15:00:13.292812Z","id":"CVE-2026-54590","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-10T15:00:21.849Z"}}]}}