CVE-2026-54590

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 62/100
Published: 2026-07-08 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Network No Auth No Interaction Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: None
S: Unchanged
C: None
I: High
A: None

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. Version 2.23.0 contains an incomplete fix for CVE-2026-45309 in SSHServerConfig._set_tokens that blocks /, , and .. before %u substitution in AuthorizedKeysFile but does not block a leading ~ or ${ENV}, allowing later expansion in _expand_val and Path(filename).expanduser() to escape the intended authorized-keys directory. This issue is fixed in version 2.23.1.

Weakness Classification (2)

Bug Bounty Relevance

62 / 100
✓ Network accessible
✓ No authentication
✓ No user interaction

CVSS Score

5.9 / 10.0 v3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS — Exploitation Probability

0.34%
Raw Score 0.003360
Percentile 27.0%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00336
2026-10-28
0.00336

Intelligence Sources

nvd ref →