A cryptographic cache-based side channel in the RSA implementation in Botan before 1.10.17, and 1.11.x and 2.x before 2.3.0, allows a local attacker to recover information about RSA secret keys, as demonstrated by CacheD. This occurs because an array is indexed with bits derived from a secret key.
https://www.usenix.org/conference/usenixsecurity17/technical-sessions/presentation/wang-shuai
https://lists.debian.org/debian-lts-announce/2021/11/msg00006.html