PostgreSQL -- Selectivity estimators bypass row security policies

The PostgreSQL project reports:

    PostgreSQL maintains statistics for tables by sampling
    data available in columns; this data is consulted during
    the query planning process. Prior to this release, a user
    able to execute SQL queries with permissions to read a
    given column could craft a leaky operator that could
    read whatever data had been sampled from that column.
    If this happened to include values from rows that the user
    is forbidden to see by a row security policy, the user
    could effectively bypass the policy. This is fixed by only
    allowing a non-leakproof operator to use this data if
    there are no relevant row security policies for the table.