Answer in brief
CVE-2026-128087 records a Low severity (CVSS 3.7) vulnerability in russh kex_done: shared-secret callback runs before server host-key verification. The current sources do not mark it as known exploited. The current feed maps russh (crates.io), Eugeny/russh (generic), russh (rust). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps russh (crates.io), Eugeny/russh (generic), russh (rust). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| russhcrates.io | >=0.55.0 <0.65.1 | 0.65.1 |
| Eugeny/russhgeneric | >=0.55.0 <0.65.1 | 0.65.1 |
| russhrust | >=0.55.0,<0.65.1 | 0.65.1 |
Published upstream
Nov 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 13, 2026
russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. From version 0.55.0 until version 0.65.1, the initial key exchange invokes client::Handler::kex_done() with the raw shared secret before check_server_key() accepts the server host key or certificate. A malicious SSH server can therefore trigger application-defined secondary-channel initialization or early data handling even when the server identity is subsequently rejected. Ordinary clients that keep the callback's no-op default or independently defer callback-derived actions until trust is confirmed are not affected. This issue is fixed in version 0.65.1.
Quoted source text, attributed separately from HOL analysis.