GHSA-G9F8-WQJ9-FJW5 Russh: Unchecked CryptoVec allocation and growth handling is reachable

Title Unchecked CryptoVec allocation and growth handling was reachable from local agent inputs in current russh releases and from remote SSH traffic in historical pre-0.58.0 releases Summary CryptoVec used unchecked capacity growth, unchecked length arithmetic, and unsafe allocation/locking paths...