CVSS 3.1
6.5 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:NCVE-2026-77473
Medium (6.5) in ronf asyncssh. EPSS 0.5% estimated probability of exploitation activity in the next 30 days.
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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 2.24.1, recursive remote-to-local SFTP copies in SFTPClient._copy() in asyncssh/sftp.py, reached through get(), mget(), and copy(), trust filenames returned by a remote server's directory enumeration. A malicious or compromised SFTP server can return an absolute filename or a filename containing path separators and parent-directory traversal, causing destination path construction to escape the requested local directory and write attacker-selected content to locations writable by the client process. This issue is fixed in version 2.24.1.
Severity
- EPSS
- 0.5% estimated probability of exploitation activity in the next 30 days; 46th percentile. Scored 2026-11-10. A forecast for this CVE across the internet, not for your own systems.
- CWE
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory (Path traversal)
- OWASP Top 10
- A01:2025 Broken Access Control
- Published
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Not in the NVD yet
- Record from
- the CVE List, synced
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Explain CVE-2026-77473 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-77473?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-77473?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-77473 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| ronf asyncssh | < 2.24.1 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13, 14 | python-asyncssh | no fix listed | DEBIAN-CVE-2026-77473 |
From the distributions' data via OSV.dev: the Debian Security Tracker. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian.
Attack patterns (CAPEC)
- CAPEC-64 Using Slashes and URL Encoding Combined to Bypass Validation Logic Likelihood: High · Severity: High
- CAPEC-76 Manipulating Web Input to File System Calls Likelihood: High · Severity: Very High
- CAPEC-78 Using Escaped Slashes in Alternate Encoding Likelihood: High · Severity: High
- CAPEC-79 Using Slashes in Alternate Encoding Likelihood: High · Severity: High
- CAPEC-126 Path Traversal Likelihood: High · Severity: Very High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.