CVE-2026-54591: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in ronf asyncssh
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 2.23.1, a malicious SSH server can write arbitrary files on the asyncssh SCP client's filesystem by sending filenames containing ../ traversal sequences because _parse_cd_args in scp.py returns server-provided names verbatim and _recv_files joins them to the destination path without enforcing the target directory boundary. This issue is fixed in version 2.23.1.
AI Analysis
Technical Summary
AsyncSSH is a Python package implementing SSHv2 asynchronously. Before version 2.23.1, the SCP client improperly handles server-supplied filenames containing path traversal sequences ('../'). The function _parse_cd_args returns these names verbatim, and _recv_files joins them to the destination path without enforcing directory boundaries. This allows a malicious SSH server to write arbitrary files anywhere on the client's filesystem. The vulnerability is fixed in version 2.23.1.
Potential Impact
An attacker controlling an SSH server can cause the AsyncSSH SCP client to write files arbitrarily on the client's filesystem, potentially overwriting critical files or placing malicious files. This can lead to integrity and availability impacts on the client system. Confidentiality impact is not indicated. No known exploits in the wild have been reported.
Mitigation Recommendations
Upgrade AsyncSSH to version 2.23.1 or later where this path traversal vulnerability is fixed. No other mitigations are specified. Patch status is confirmed by the version fix indication.
CVE-2026-54591: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in ronf asyncssh
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 2.23.1, a malicious SSH server can write arbitrary files on the asyncssh SCP client's filesystem by sending filenames containing ../ traversal sequences because _parse_cd_args in scp.py returns server-provided names verbatim and _recv_files joins them to the destination path without enforcing the target directory boundary. This issue is fixed in version 2.23.1.
CVSS v3.1
Score 8.1high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
AsyncSSH is a Python package implementing SSHv2 asynchronously. Before version 2.23.1, the SCP client improperly handles server-supplied filenames containing path traversal sequences ('../'). The function _parse_cd_args returns these names verbatim, and _recv_files joins them to the destination path without enforcing directory boundaries. This allows a malicious SSH server to write arbitrary files anywhere on the client's filesystem. The vulnerability is fixed in version 2.23.1.
Potential Impact
An attacker controlling an SSH server can cause the AsyncSSH SCP client to write files arbitrarily on the client's filesystem, potentially overwriting critical files or placing malicious files. This can lead to integrity and availability impacts on the client system. Confidentiality impact is not indicated. No known exploits in the wild have been reported.
Mitigation Recommendations
Upgrade AsyncSSH to version 2.23.1 or later where this path traversal vulnerability is fixed. No other mitigations are specified. Patch status is confirmed by the version fix indication.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-15T19:45:23.539Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4eb690c9d9e3dbe3b6872a
Added to database: 07/08/2026, 20:44:00 UTC
Last enriched: 07/16/2026, 10:04:52 UTC
Last updated: 08/22/2026, 22:52:14 UTC
Views: 60
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