GHSA-f5v4-2wr6-hqmg: russh has pre-auth DoS via unbounded allocation in its keyboard-interactive auth handler

April 24, 2026

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.

References

github.com/Eugeny/russh
github.com/Eugeny/russh/commit/6c3c80a9b6d60763d6227d60fa8310e57172a4d1
github.com/Eugeny/russh/releases/tag/v0.60.1
github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg
github.com/advisories/GHSA-f5v4-2wr6-hqmg

Code Behaviors & Features

Detect and mitigate GHSA-f5v4-2wr6-hqmg with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →