CVE-2026-54591

AsyncSSH: SCP Path Traversal to Arbitrary File Write

HIGH
8.1
CVSS Score
Published: July 8, 2026 at 08:33 PM UTC
Updated: October 25, 2026 at 05:10 PM UTC
1 product affected across 1 vendorAsyncssh

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Severity
HIGH8.1
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.23.1
Affected range stops below 2.23.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-22

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