CVE-2026-54591: AsyncSSH: SCP Path Traversal to Arbitrary File Write
Vulnerability summary
CVE-2026-54591 is a high (CVSS 8.1) vulnerability in ronf asyncssh. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 42.3% of scored vulnerabilities.
Not severe (CVSS 8.1, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 0 · Related 1Timeline
- 08-07-2026PublishedVulnerability first disclosed.
- 09-07-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
6 scores · 6 sources · 1 version- OSV · PypiEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
- OSV · ChainguardEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
- NVDNIST8.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
EPSS trend
Probability
0.49%
Chance of exploitation in the next 30 days
Percentile
42%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.49% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard1 product
- airflow-2< 2.11.2-r17
Debian1 product
- python-asyncsshAll versions (No fix recorded) | < 2.24.0-1
PyPI1 product
- asyncssh< 2.23.1
Ronf1 product
- asyncssh< 2.23.1
Ubuntu1 product
- python-asyncsshAll versions (No fix recorded)
5 vendors · 5 products
References
11 links- github.com/ronf/asyncssh/security/advisories/GHSA-2wxc-x7rj-hg8fX Refsource CONFIRMWEBREPORTAdvisory
- github.com/ronf/asyncssh/commit/d730803b8e4e94c20c7580d90f94d1e05f9f58deX Refsource MISCWEBREPORTFIX
- github.com/ronf/asyncsshPACKAGE
- pypi.org/project/asyncsshPACKAGE
