Wireshark 0.99.7 has been released. Many security-related vulnerabilities have been fixed. See the advisory for details.
This release improves the privilege separation between the capture code and interface code. It also lets you filter directly on SNMP OIDs, follow UDP streams, and has improved Vista support. For a complete list of changes, please refer to the 0.99.7 release notes. Official releases are available right now from the download page.