vBulletin 4.1.2
vBSEO 3.6.0

The Acronym expansion module in the vBSEO does not handle non-ASCII characters correctly.

The expansion should only be done on full words and not on word parts, for example:

SEO -> Search Engine Optimization

betterseo -> no expansion

How ever, if the word contains non-ascii characters such as ä ö å ü and one of those characters happen to be right after the acronym that is configured to be expanded, the vBSEO expands the term middle of the word. For example:

We have defined acronym expansion PES => Pro Evolution Soccer

Correct behavior:

pes -> the word is expanded to pro evolution soccer
pesapallo -> no expansion is done

Incorrect behavior:

pesäpallo -> the beginning of the word is expanded to pro evolution soccer