Path Traversal in Ronf Asyncssh
CVE-2026-54591
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.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.003 (24.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H.
Affected products
- Ronf Asyncssh — versions < 2.23.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-54591?
- CVE-2026-54591 is a high-severity vulnerability in Ronf Asyncssh, classified under Path Traversal. CVSS score: 8.1/10. Published 2026-07-08.
- How severe is CVE-2026-54591?
- High severity. CVSS v3 base score is 8.1 out of 10.