
The Firefox 1.5.0.5 release was originally scheduled for today but Mozilla has posted the release notes page and it has a release date of July 27 on it. I still think that they may be releasing it a little sooner because normally when they get the release notes page up that means the official release is soon to follow. Also, it appears that they were able to get the update files posted to the Mozilla FTP which are the files that Firefox uses to update itself. Even though the update files are there they have not posted the full downloads yet.
This release is only to increase Firefox’s stability and to address some security issues:
- Improvements to product stability
- Added changes for Frisian locale (fy-NL)
- Several security fixes
The link above that lists the security fixes has not been updated for Firefox 1.5.0.5 yet but it probably will be shortly.

As far as I’m aware, Mozilla’s policy is to release security fixes a day after the fixes are available. That way, users have a chance to protect themselves before malicious attacks can be composed.
It was delayed due to a bug fix such as Bug#344249
See the mozilla.dev.planning newsgroup.
The known-vulnerabilities page will get the listedsecurity fixes soon however it is not uncommon for some security sensitive bugs mentioned in each that have limited group access to stay limited access for a couple of weeks to months after release depending.