CVE-2026-54591Public exploitNetwork attack vector

Arbitrary file write via SCP path traversal

Published Jul 8, 2026 · Updated Jul 8, 2026

Path traversal in AsyncSSH before 2.23.1 allows remote attackers controlling an SSH server to write arbitrary client-side files. _parse_cd_args returns server-provided SCP names verbatim, and _recv_files joins them to the destination without enforcing its directory boundary. Exploitation requires a user or application to download via SCP from the malicious server; overwriting startup or SSH files can execute code later.

CVSS severity8.1
High
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in AsyncSSH before 2.23.1 allows remote attackers controlling an SSH server to write arbitrary client-side files. _parse_cd_args returns server-provided SCP names verbatim, and _recv_files joins them to the destination without enforcing its directory boundary. Exploitation requires a user or application to download via SCP from the malicious server; overwriting startup or SSH files can execute code later.

The record

CVE
CVE-2026-54591
Published
Jul 8, 2026
Updated
Jul 8, 2026
Vendor
Ron Frederick
Product
AsyncSSH
Classifications
CWE-22, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.23.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ron Frederick · AsyncSSHversion=< 2.23.1

Published CVSS scores

8.1GitHub CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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