The hickory-proto library versions from 0.3.1 up to but not including 0.26.1 contain a vulnerability in the BinEncoder's name compression logic. This vulnerability arises because the encoder stores candidate labels for name compression in a vector and performs a linear scan to find matches, resulting in O(n²) complexity. An attacker can exploit this by crafting messages with many records, causing excessive CPU usage and potential denial-of-service (DoS). A fix is available in version 0.26.1.