The versions listed below are known to be affected by this issue. If you are using one of those versions, you should update to a newer release that has no known vulnerabilities.
Common Name Tag Duplication Vulnerability VWE-ID VWE-2015-1812 Related Report None Severity Extreme Exploit Difficulty EASY Platform XenForo Description Denial of Service.
Discovered November 10, 2015 Resolved November 11, 2015 Patches Available 4.0.7 Patch Level 1
4.0.6 Patch Level 4
4.0.5 Patch Level 4
4.0.4 Patch Level 4
4.0.3 Patch Level 4
4.0.2 Patch Level 7
4.0.1 Patch Level 10
4.0.0 Patch Level 9
4.0.0 RC 5 Patch Level 8Workaround In the AdminCP, go to Tools > Cron Entries. Find "Rebuild Sitemap" in the list, and use Controls to Disable it.