parcimonie before 0.8.1, when using a large keyring, sleeps for the same amount of time between fetches, which allows attackers to correlate key fetches via unspecified vectors.
Concurrent Execution using Shared Resource with Improper Synchronization The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.