github.com/nwaples/rardecode versions <=2.1.1 fail to restrict the dictionary size when reading large RAR dictionary sizes, which allows an attacker to provide a specially crafted RAR file and cause Denial of Service via an Out Of Memory Crash.
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.