CVE-2026-42189 Details
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.
A denial-of-service vulnerability has been identified in the Russh library, which is a Rust SSH client and server library. This issue, present in versions through 0.58.0, arises in the server's keyboard-interactive authentication handler. A malicious client can exploit this vulnerability by sending a single malformed packet, without needing any credentials, to crash any Russh-based server that supports keyboard-interactive authentication, such as for two-factor authentication or TOTP. The vulnerability causes the server to allocate excessive memory, leading to an out-of-memory condition and a process crash.
Users can upgrade to Russh version 0.60.1 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 11, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/Eugeny/russh/commit/6c3c80a9b6d60763d6227d60fa8310e57172a4d1 | [email protected] | Patch |
| https://github.com/Eugeny/russh/releases/tag/v0.60.1 | [email protected] | ProductRelease Notes |
| https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-770 | Allocation of Resources Without Limits or Throttling | [email protected] |
| CWE-789 | Memory Allocation with Excessive Size Value | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| russh project russh | < 0.60.1 |
CPE
Remediation
| |
| warpgate project warpgate | < 0.23.1 |
CPE
Remediation
| |
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 14, 2026 | Initial Analysis | [email protected] |
| May 11, 2026 | CVE Modified | CISA-ADP |
| May 8, 2026 | New CVE Received | [email protected] |