CVE-2026-42189
russh has pre-auth DoS via unbounded allocation in its keyboard-interactive auth handler
7.5
HIGH
CVSS 3.1
EPSS 0.48%
Description
Russh is a Rust SSH client & server library. Prior to version 0.60.1, a pre-authentication denial-of-service vulnerability exists in the server's keyboard-interactive authentication handler. A malicious client can crash any russh-based server that implements keyboard-interactive auth (e.g., for 2FA/TOTP) with a single malformed packet, requiring no credentials. This issue has been patched in version 0.60.1.
How to fix CVE-2026-42189
To remediate CVE-2026-42189, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 0.60.1 or later
Is CVE-2026-42189 being exploited?
Low — EPSS is 0.5%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- from 0, < 0.60.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |