The core server component in PostgreSQL 8.4 before 8.4.1, 8.3 before 8.3.8, and 8.2 before 8.2.14 allows remote authenticated users to cause a denial of service (backend shutdown) by "re-LOAD-ing" libraries from a certain plugins directory.

PostgreSQL before 8.3.7, 8.2.13, 8.1.17, 8.0.21, and 7.4.25 allows remote authenticated users to cause a denial of service (stack consumption and crash) by triggering a failure in the conversion of a localized error message to a client-specified encoding, as demonstrated using mismatched encoding conversion requests.