CVE-2026-45309
Description
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.
How to fix
- asyncssh_project asyncssh2.23.0 or later
- asyncssh2.23.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| asyncssh_project asyncssh | v < 2.23.0 | 2.23.0 |
| asyncsshPyPI | 2.22.0 ≤ v < 2.23.0 | 2.23.0 |
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