CVE-2026-54590: fallo de gravedad media en ronf asyncssh
AsyncSSH AuthorizedKeysFile username substitution bypass through ~ and environment expansion
Publicada el · Actualizada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
13Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 5.9epss 0.3%
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Productos afectados
ronf · asyncsshCVEs relacionadas — ronf asyncssh
En el mismo producto, de las más peligrosas a las menos.
CVE-2026-45309HIGHAsyncSSH `AuthorizedKeysFile %u` path traversal allows attacker-selected authorized keys to authenticate a traversal usernameEPSS 0.6%CVE-2026-54591HIGHAsyncSSH: SCP Path Traversal to Arbitrary File WriteEPSS 0.5%CVE-2026-62949MEDIUMAsyncSSH: asyncio event-loop freeze via SSH maximum packet size = 0 in SSH_MSG_CHANNEL_OPEN / OPEN_CONFIRMATIONEPSS 0.4%