Upstream has released  versions 4.2rc1, 4.0.3, 3.6.7, and 3.4.13 to correct two security issues:
* When a user creates a new account, Bugzilla doesn't correctly reject email addresses containing non-ASCII characters, which could be used to impersonate another user account. (CVE-2012-0448)
* A CSRF vulnerability in the implementation of the JSON-RPC API could be used to make changes to bugs or execute some admin tasks without the victim's knowledge. (CVE-2012-0440)
Sorry, those flaws _affect_ the cited versions above, and are fixed in 4.2rc2, 4.0.4, 3.6.8, and 3.4.15. Also note that CVE-2012-0440 does _not_ affect 3.4.x.
Created bugzilla tracking bugs for this issue
Affects: fedora-all [bug 786550]
Affects: epel-all [bug 786551]
This was fixed with an update a while ago in Fedora.
bugzilla-4.0.4-1.fc16 has been pushed to the Fedora 16 stable repository. If problems still persist, please make note of it in this bug report.
bugzilla-3.6.8-1.fc15 has been pushed to the Fedora 15 stable repository. If problems still persist, please make note of it in this bug report.