CVE-2026-42189CWE-770CWE-789

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

High · published May 8, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
54.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00758 · 54.7th percentile
Weaknesses
CWE-770 · Allocation of Resources Without Limits or Throttling; CWE-789 · Memory Allocation with Excessive Size Value
Published
2026-05-08T19:49Z
EPSS history
Timeline
  • 08 MAY 19:49Z
    Russh: Pre-auth DoS via unbounded allocation in keyboard-interactive auth
    cvelistv5