CVE-2026-45309AsyncSSH `AuthorizedKeysFile %u` path traversal allows attacker-selected authorized keys to authenticate a traversal username
- 8.2HighCVSS base score
- 0.59%Exploitation in 30 daysEPSS · top 51% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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 2.23.0, AsyncSSH expands the OpenSSH-compatible AuthorizedKeysFile %u token in asyncssh/config.py, asyncssh/connection.py, asyncssh/auth_keys.py, and asyncssh/misc.py with the raw SSH username during pre-authentication server config reload, allowing a server configured with AuthorizedKeysFile authorized_keys/%u to read an authorized-keys file outside the intended directory when the SSH username contains /, \, or .. path traversal segments and authenticate with an attacker-selected key file. This issue is fixed in version 2.23.0.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/ronf/asyncssh/security/advisories/GHSA-g794-3fmp-753h (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
- 4 days later
· 4 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | High8.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N |
| NVDNVD · Analyzed | 4.0 | High8.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.59% · top 51% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIasyncsshGHSA-g794-3fmp-753h (opens in a new tab)
References
References3
- https://github.com/ronf/asyncssh/security/advisories/GHSA-g794-3fmp-753h (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/ronf/asyncssh/commit/2af2382cce946c959a378a62f257af253dc4ab51 (opens in a new tab)x_refsource_MISC
- https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45255 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-g794-3fmp-753h (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-45309)Record last updated .