Russh is a Rust SSH client & server library. From version 0.34.0-beta.1 to before version 0.61.0, the russh server authentication path keeps internal userauth state across SSH_MSG_USERAUTH_REQUEST messages without separating that state when the request principal changes. RFC 4252 allows the user name and service name fields to change between authentication requests. The issue is not that such changes are invalid. The issue is that russh-owned authentication state, such as remaining methods, partial-success state, and in-progress method state, can remain associated with the connection and then influence a later request for a different (user, service). This is an internal library state mismatch. This issue has been patched in version 0.61.0.
History

Thu, 11 Jun 2026 01:45:00 +0000

Type Values Removed Values Added
First Time appeared Eugeny
Eugeny russh
Vendors & Products Eugeny
Eugeny russh

Wed, 10 Jun 2026 21:00:00 +0000

Type Values Removed Values Added
Description Russh is a Rust SSH client & server library. From version 0.34.0-beta.1 to before version 0.61.0, the russh server authentication path keeps internal userauth state across SSH_MSG_USERAUTH_REQUEST messages without separating that state when the request principal changes. RFC 4252 allows the user name and service name fields to change between authentication requests. The issue is not that such changes are invalid. The issue is that russh-owned authentication state, such as remaining methods, partial-success state, and in-progress method state, can remain associated with the connection and then influence a later request for a different (user, service). This is an internal library state mismatch. This issue has been patched in version 0.61.0.
Title russh server userauth state is not reset when authentication principal changes
Weaknesses CWE-287
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-10T20:22:20.209Z

Reserved: 2026-05-15T23:26:58.309Z

Link: CVE-2026-46705

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-06-10T22:17:00.713

Modified: 2026-06-10T22:17:00.713

Link: CVE-2026-46705

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-11T01:30:36Z