High 7.5Published Sep 29, 2026

CVE-2026-102823russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened

Updated under an hour ago (2026-10-19 10:00 UTC)

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It affects Eugeny russh. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.26%, higher than 17% of scored CVEs.

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Every CVE for Eugeny russh

Exploited in the last 30 days

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.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-20
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.26% (percentile 17)
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 2, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Eugeny russh eugeny:russh (from the name)	before 0.63.1	CNA record

References

https://github.com/Eugeny/russh/security/advisories/GHSA-47hw-gvq5-r2gmx-refsource-confirm
https://github.com/Eugeny/russh/commit/3430fd26ecafc0dc3705210f5f39a9119fa22774x-refsource-misc
https://github.com/Eugeny/russh/releases/tag/v0.63.1x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.