Description
Russh is a Rust SSH client and server library. Prior to 0.63.1, client_read_authenticated in russh/src/client/encrypted.rs forwards CHANNEL_DATA, CHANNEL_EXTENDED_DATA, CHANNEL_EOF, CHANNEL_CLOSE, CHANNEL_OPEN_FAILURE, CHANNEL_SUCCESS, CHANNEL_FAILURE, and CHANNEL_REQUEST subtypes exit-status, exit-signal, and xon-xoff to public client::Handler callbacks without confirming that the ChannelId belongs to a channel the client opened and established. A malicious SSH server can send lifecycle events for predicted, unopened, unconfirmed, or released channel identifiers, causing application panics or corrupting command completion and exit-code tracking. This issue is fixed in version 0.63.1.
Published: 2026-09-29
Score: 7.5 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Tue, 29 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
Description Russh is a Rust SSH client and server library. Prior to 0.63.1, client_read_authenticated in russh/src/client/encrypted.rs forwards CHANNEL_DATA, CHANNEL_EXTENDED_DATA, CHANNEL_EOF, CHANNEL_CLOSE, CHANNEL_OPEN_FAILURE, CHANNEL_SUCCESS, CHANNEL_FAILURE, and CHANNEL_REQUEST subtypes exit-status, exit-signal, and xon-xoff to public client::Handler callbacks without confirming that the ChannelId belongs to a channel the client opened and established. A malicious SSH server can send lifecycle events for predicted, unopened, unconfirmed, or released channel identifiers, causing application panics or corrupting command completion and exit-code tracking. This issue is fixed in version 0.63.1.
Title russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened
Weaknesses CWE-20
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-29T18:25:58.084Z

Reserved: 2026-09-29T17:25:25.265Z

Link: CVE-2026-102823

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-09-29T19:17:24.367

Modified: 2026-09-29T19:17:24.503

Link: CVE-2026-102823

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-20

    Improper Input Validation