See: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1498 Upgrading to 1.5.8 should fix this, this probably affects other repors / releases then Development too.
1.5.8 has been in all FE4+ repos since April 3rd based on file timestamps.
My bad I ran yum list "*mediawiki*" and that said 1.5.7, but that is because when run as user yum doesn't update its metadata. Was mediawiki in FE3 too? Ifso 1.5.8 or another fix should be pushed for FE3, even though FE3 is eol, security fixes should still be applied by package maintainers. (other updates should not).
mediawiki is only in FE-4, FE-5, and devel [kaboom@fc5test extras]$ cvs co mediawiki <snip> [kaboom@fc5test extras]$ ls mediawiki/ common CVS devel FC-4 FC-5 import.log Makefile [kaboom@fc5test extras]$