CVE-2026-102823
russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rust | russh | <= 0.63.0 | 0.63.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-47hw-gvq5-r2gm
- https://github.com/Eugeny/russh/security/advisories/GHSA-47hw-gvq5-r2gm
- https://nvd.nist.gov/vuln/detail/CVE-2026-102823
- https://github.com/Eugeny/russh/commit/3430fd26ecafc0dc3705210f5f39a9119fa22774
- https://github.com/Eugeny/russh/releases/tag/v0.63.1