We have released new versions of both psycopg 2 and 3 packages, addressing the security issue CVE-2021-23222, affecting the libpq and which has been resolved in PostgreSQL 14.1 and in the other versions provided in the same release [1].
The new psycopg releases only solve the problem in the binary packages: if you install psycopg from source you will need to upgrade the system libpq library instead.
In order to verify what libpq version your system is using you can query the functions 'psycopg2.extensions.libpq_version()' [2] and 'psycopg.pq.version()' [3].