CVE-2026-54591

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-08 21:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-25 17:10 UTC Last updatedMost recent change to the record

Details

Published

2026-07-08 21:16 UTC

Last modified

2026-10-25 17:10 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-22 · Path traversal

Record status

Deferred

Attack profile CVSS 3.1 · 8.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

High