Today the PostgreSQL Global Development Group is releasing updated versions which patch five security vulnerabilities. These releases update all current PostgreSQL versions, including 8.2, 8.1, 8.0, 7.4 and 7.3. They are considered CRITICAL and PostgreSQL DBAs and sysadmins should install the update as soon as they reasonably can. Our security team has made all efforts to make these patches backwards-compatible, and upgrading does not require converting your data files.

http://www.securiteam.com/unixfocus/5SP0220N5M.html