CVE-2026-54591

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 76% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
8.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.1Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
8.1
EG Score
8.1(medium)
EPSS
23.7%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 10, 2026

Advisory Details (2)

Auto-updated Jul 8, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github_commit

commit d730803b8e4e (ronf/asyncssh)

Fix landed in ronf/asyncssh commit d730803b8e4e — awaiting tagged release

https://github.com/ronf/asyncssh/commit/d730803b8e4e94c20c7580d90f94d1e05f9f58de
github Patch Available🟡 PoC Available

SCP Path Traversal to Arbitrary File Write · Advisory · ronf/asyncssh · GitHub

https://github.com/ronf/asyncssh/security/advisories/GHSA-2wxc-x7rj-hg8f

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 25× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-15 21:04 UTCEG score recompute
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 08:06 UTCEG score recompute
  5. 2026-07-15 02:00 UTCEPSS rescore
  6. 2026-07-15 02:00 UTCEPSS rescore
  7. 2026-07-14 19:08 UTCEG score recompute
  8. 2026-07-14 06:09 UTCEG score recompute
  9. 2026-07-13 22:31 UTCEPSS rescore
  10. 2026-07-13 17:13 UTCEG score recompute
  11. 2026-07-13 06:13 UTCEPSS rescore
  12. 2026-07-13 06:13 UTCEPSS rescore
  13. 2026-07-13 04:17 UTCEG score recompute
  14. 2026-07-12 15:20 UTCEG score recompute
  15. 2026-07-12 05:46 UTCEPSS rescore
  16. 2026-07-12 02:23 UTCEG score recompute
  17. 2026-07-11 13:27 UTCEG score recompute
  18. 2026-07-11 08:27 UTCEPSS rescore
  19. 2026-07-11 08:27 UTCEPSS rescore
  20. 2026-07-11 00:31 UTCEG score recompute
  21. 2026-07-10 11:35 UTCEG score recompute
  22. 2026-07-09 22:36 UTCEG score recompute
  23. 2026-07-09 19:10 UTCEPSS rescore
  24. 2026-07-09 19:10 UTCEPSS rescore
  25. 2026-07-09 09:40 UTCEG score recompute
Show 2 more
  1. 2026-07-08 20:44 UTCEG score recompute
  2. 2026-07-08 20:44 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-54591?
CVE-2026-54591 is a high vulnerability published on July 8, 2026. 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 ../…
When was CVE-2026-54591 disclosed?
CVE-2026-54591 was first published in the National Vulnerability Database on July 8, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54591 actively exploited?
CVE-2026-54591 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 23.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54591?
CVE-2026-54591 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-54591?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54591, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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