CVE 2009-0922
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.
See the 
CVE page on Mitre.org
for more details.
