There are 2 open security issues in bullseye.
2 issues left for the package maintainer to handle:
The ElGamal implementation in Botan through 2.18.1, as used in Thunderbird and other products, allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.
In Botan before 2.19.3, it is possible to forge OCSP responses due to a certificate verification error. This issue was introduced in Botan 1.11.34 (November 2016).
You can find information about how to handle these issues in the security team's documentation.