Scientists Believe These Photos Show Mushrooms on Mars–and Proof of Life (opens in new tab)

This paper has not actually been published yet... (The article links to a paper-like thing in "ResearchGate" -- which then suggests it may be published in the upcoming fungus issue of the journal.)

But even that journal came in for some criticism from CNET:

https://www.cnet.com/news/sorry-nasa-photos-are-not-evidence...

The real bugaboo seems to be Mr. Joseph (one of the authors), who has a really bad history of insisting he's found life on other planets, dating back to the 1970s.

https://thenextweb.com/news/mushrooms-mars-hoax-nasa-rover-d...

I just happened to find this 2017 article about fungi growing on the exterior of the space station. I wouldn't be surprised if extremophile fungi turn out to be widespread in space after all http://cosmology.com/SpaceFungi.html