CVE-2026-128087

CVSS 3.7 (low) · published 2026-11-13

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.

Weakness: CWE-696, CWE-863

Source: NVD CVE-2026-128087

References

• https://github.com/Eugeny/russh/commit/43a46d67a80a7355fcd2fb25e7e00d79aec8184c
• https://github.com/Eugeny/russh/pull/808
• https://github.com/Eugeny/russh/releases/tag/v0.65.1
• https://github.com/Eugeny/russh/security/advisories/GHSA-9264-jvgf-6w2f
• https://github.com/Eugeny/russh/security/advisories/GHSA-9264-jvgf-6w2f

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