Movable Type 4.38 patch to fix a known upgrading security issue Six Apart has found a security issue and fixed it in Movable Type 4.2 and MT 4.3. For those of you who use Movable Type 4.2 and 4.3, Six Apart strongly recommends that you upgrade to the latest released version of Movable Type or execute the following steps immediately. This vulnerability does not exist in Movable Type versions 5.0 or