SSH Library Vulnerability in russh by Eugeny

CVE-2026-111062

What is CVE-2026-111062?

The russh library, which serves as a Rust implementation of an SSH client and server, is susceptible to a vulnerability that arises from its handling of public-key authentication. Versions from 0.34.0-beta.1 to 0.64.0 do not enforce a requirement for the signature algorithm in authentication requests to match the specified algorithm. This could allow an attacker with a valid RSA private key to exploit the library by claiming to use an rsa-sha2-512 signature while providing a valid ssh-rsa SHA-1 signature instead. Such misconfigurations could lead to potential bypass of security restrictions and unreliable audit logs if reliant on the specified algorithm. This issue has been resolved in russh version 0.64.0.

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