GHSA-2wxc-x7rj-hg8f: asyncssh (CVE-2026-54591)

Package	Ecosystem	Affected	Fixed in
asyncssh	PyPI	<2.23.1	2.23.1

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

A malicious SSH server can write files outside the intended directory on the client in asyncssh versions through 2.23.0, because the SCP receive path does not sanitize server-supplied filenames containing "../" sequences. An attacker controlling the server can overwrite files such as ~/.bashrc or ~/.ssh/authorized_keys, which can lead to code execution on the client. Upgrade asyncssh to version 2.23.1 or later.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
8.1	High	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0049, the 42nd percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:10 UTC First seen by agentprime
31 Oct 2026, 14:10 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.