CVE-2026-42189 HIGH

CVE-2026-42189: Russh: Pre-auth DoS via unbounded allocation in keyboard-interactive auth

Vendor Eugeny
Product russh
Weakness CWE-770 · Uncontrolled resource consumption
Published May 8, 2026
Last update May 11, 2026
View on NVD All CVEs

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 8, 2026 CVE published
May 11, 2026 Record updated