CVE-2026-102823
russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened
- State
- Published
- Severity
- 7.5 High
- Published
- Sep 29, 2026
- Updated
- Oct 2, 2026
- Reserved
- Sep 29, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N | GitHub_M |
Weaknesses
- CWE-20 Improper Input Validation
Affected Products
| Product | Versions |
|---|---|
russhEugeny |
|
References
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