# CVE-2026-45309: python-asyncssh: AsyncSSH is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on...

CVE-2026-45309 is fixed in python-asyncssh on 1 platform by DEBIAN-CVE-2026-45309 (version 2.23.0-1), released July 10, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-45309
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0059
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 17, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-asyncssh Debian 14 | 2.23.0-1 | [DEBIAN-CVE-2026-45309](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45309.md) | Jul 10, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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