Once again, do not confuse WikiMedia Commons with WikiPedia.
I’m only talking about the endless articles on made-up sex acts on Wikipedia, many of which have ridiculous line drawings or amateur photos accompanying them. Wikipedia itself has endless examples of writing-articles-as-fetishism. I don’t care much about pictures uploaded to a Wikipedia sister site that aren’t used on Wikipedia, though it is worth noting that the entire Wikimedia/Wikia enterprise is owned and operated by a common group of people, so treating them as separate entities is not wholly accurate.
The closet thing I’ve seen that some might consider kiddie porn is the article about the rock group The Scorpions’ album Virgin Killer. It contains a picture of the original album cover which consists of a completely nude 12-year-girl posing full-frontal (with just a fake glass crack covering her who-ha).
The girl was a professional model and her mother was on-set when it was taken. She’s now an adult and says she has no regrets about it and in fact is proud of the photo.