CVE-2026-54590

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Source
https://cve.org/CVERecord?id=CVE-2026-54590
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54590.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-54590
Aliases
  • GHSA-qr67-gv47-xwwh
Downstream
Published
2026-07-08T20:36:45.258Z
Modified
2026-08-04T11:48:46.578378715Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
Summary
AsyncSSH AuthorizedKeysFile username substitution bypass through ~ and environment expansion
Details

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.settokens that blocks /, , and .. before %u substitution in AuthorizedKeysFile but does not block a leading ~ or ${ENV}, allowing later expansion in expandval and Path(filename).expanduser() to escape the intended authorized-keys directory. This issue is fixed in version 2.23.1.

Database specific 
{
    "cwe_ids": [
        "CWE-22",
        "CWE-639"
    ],
    "cna_assigner": "GitHub_M",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54590.json"
}
References

Affected packages

Git / github.com/ronf/asyncssh

Affected ranges

Type
GIT
Repo
https://github.com/ronf/asyncssh
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
1b5839f3827f7bf546fc311cc8da77788a9d22f7
Database specific 
{
    "source": "AFFECTED_FIELD",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.23.1"
        }
    ]
}

Affected versions

v0.*
v0.1.0
v0.2.0
v0.3.0
v0.4.0
v0.5.0
v0.6.0
v0.7.0
v0.8.0
v0.8.1
v0.8.2
v0.8.3
v0.8.4
v0.9.0
v0.9.1
v0.9.2
v1.*
v1.0.0
v1.0.1
v1.1.0
v1.1.1
v1.10.0
v1.10.1
v1.11.0
v1.11.1
v1.12.0
v1.12.1
v1.12.2
v1.13.0
v1.13.1
v1.13.2
v1.13.3
v1.14.0
v1.15.0
v1.15.1
v1.16.0
v1.16.1
v1.17.0
v1.17.1
v1.18.0
v1.2.0
v1.2.1
v1.3.0
v1.3.1
v1.3.2
v1.4.0
v1.4.1
v1.5.0
v1.5.1
v1.5.2
v1.5.3
v1.5.4
v1.5.5
v1.5.6
v1.6.0
v1.6.1
v1.6.2
v1.7.1
v1.7.2
v1.7.3
v1.8.0
v1.8.1
v1.9.0
v2.*
v2.0.0
v2.0.1
v2.1.0
v2.10.0
v2.10.1
v2.11.0
v2.12.0
v2.13.0
v2.13.1
v2.13.2
v2.14.0
v2.14.1
v2.14.2
v2.15.0
v2.16.0
v2.17.0
v2.18.0
v2.19.0
v2.2.0
v2.2.1
v2.20.0
v2.21.0
v2.21.1
v2.22.0
v2.23.0
v2.3.0
v2.4.0
v2.4.1
v2.4.2
v2.5.0
v2.6.0
v2.7.0
v2.7.1
v2.7.2
v2.8.0
v2.8.1
v2.9.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54590.json"