{"attribution":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","cve":{"id":"CVE-2026-45309","sourceIdentifier":"security-advisories@github.com","published":"2026-07-17T19:17:14.333","lastModified":"2026-10-24T20:10:00.137","vulnStatus":"Analyzed","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. 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."},{"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. Antes de la versión 2.23.0, AsyncSSH expande el token %u de AuthorizedKeysFile compatible con OpenSSH en asyncssh/config.py, asyncssh/connection.py, asyncssh/auth_keys.py y asyncssh/misc.py con el nombre de usuario SSH sin procesar durante la recarga de la configuración del servidor de pre-autenticación, lo que permite a un servidor configurado con AuthorizedKeysFile authorized_keys/%u leer un archivo de claves autorizadas fuera del directorio previsto cuando el nombre de usuario SSH contiene segmentos de salto de ruta /, \\, o .. y autenticarse con un archivo de claves seleccionado por el atacante. Este problema está solucionado en la versión 2.23.0."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"ronf","product":"asyncssh","versions":[{"version":"\u003c 2.23.0","status":"affected"}]}]}],"metrics":{"cvssMetricV40":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":8.2,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-07-21T01:53:33.077751Z","id":"CVE-2026-45309","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-22"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:asyncssh_project:asyncssh:*:*:*:*:*:*:*:*","versionEndExcluding":"2.23.0","matchCriteriaId":"CA01D6C4-F9B2-4037-9B22-4B0A99C5DB86"}]}]}],"references":[{"url":"https://github.com/ronf/asyncssh/commit/2af2382cce946c959a378a62f257af253dc4ab51","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/ronf/asyncssh/security/advisories/GHSA-g794-3fmp-753h","source":"security-advisories@github.com","tags":["Exploit","Vendor Advisory"]},{"url":"https://github.com/ronf/asyncssh/security/advisories/GHSA-g794-3fmp-753h","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","tags":["Exploit","Vendor Advisory"]}]}}