Crypto++ 8.3.0 and earlier contains a timing side channel in ECDSA signature
generation. This allows a local or remote attacker, able to measure the
duration of hundreds to thousands of signing operations, to compute the
private key used. The issue occurs because scalar multiplication in ecp.cpp
(prime field curves, small leakage) and algebra.cpp (binary field curves,
large leakage) is not constant time and leaks the bit length of the scalar
among other information.
Based on https://github.com/weidai11/cryptopp/issues/869#issuecomment-568790184, it seems it is not appropriate to apply any patches until a release is made.