| Name | CVE-2026-54590 |
| 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. Version 2.23.0 contains an incomplete fix for CVE-2026-45309 in SSHServerConfig._set_tokens that blocks /, , and .. before %u substitution in AuthorizedKeysFile but does not block a leading ~ or ${ENV}, allowing later expansion in _expand_val and Path(filename).expanduser() to escape the intended authorized-keys directory. This issue is fixed in version 2.23.1. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1141817 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| python-asyncssh (PTS) | bullseye | 2.5.0-0.1 | fixed |
| bullseye (security) | 2.5.0-0.1+deb11u1 | fixed | |
| bookworm | 2.10.1-2+deb12u2 | fixed | |
| bookworm (security) | 2.10.1-2+deb12u1 | fixed | |
| trixie | 2.20.0-1 | fixed | |
| forky, sid | 2.23.0-1 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| python-asyncssh | source | bullseye | (not affected) | |||
| python-asyncssh | source | bookworm | (not affected) | |||
| python-asyncssh | source | trixie | (not affected) | |||
| python-asyncssh | source | (unstable) | (unfixed) | 1141817 |
[trixie] - python-asyncssh <not-affected> (Incomplete fix for CVE-2026-45309 not applied)
[bookworm] - python-asyncssh <not-affected> (Incomplete fix for CVE-2026-45309 not applied)
[bullseye] - python-asyncssh <not-affected> (Incomplete fix for CVE-2026-45309 not applied)
https://github.com/ronf/asyncssh/security/advisories/GHSA-qr67-gv47-xwwh
Fixed by: https://github.com/ronf/asyncssh/commit/3d515ba9ba0cd9990d248bdf62bcf05d51261a88 (v2.23.1)