The 30-year-old singer has responded after the 'Strawberry Lipstick' rocker covered her hit single - which is taken from her recent 'Folklore' album - for BBC Radio 1's 'Live Lounge Month' this week, and he combined it with Avril Lavigne's 2002 track 'I'm With You'.
She tweeted: "WELL this took my breath away and I'm honored to hear Cardigan intertwined with the wonderful @AvrilLavigne's masterpiece 'I'm with you'.
"Bravo and thanks @yungblud! (sic)"
Meanwhile, Machine Gun Kelly recently revealed he has three new songs with YUNGBLUD on the way.
The 'Rap Devil' hitmaker and the 23-year-old star have worked on a bunch of tracks to follow-up 2019's 'I Think I'm OKAY' from the former's LP 'Hotel Diablo', and one of them features The Used frontman Bert McCracken.
MGK revealed he wishes one of the tracks featured on his recent pop punk LP, 'Tickets to My Downfall', but it didn't for "personal reasons".
He explained: "They are so fire. The reason they aren't on the record is personal reasons.
"It's because one had a feature that we're trying to blend together, I listened to it again for the first time in a long time the other day and almost regretted not putting the energy into figuring it out earlier because I wish this song was on the album.
"I would be foolish to think that I'm not going to release a deluxe version of this by the holidays, which you would also want a reason to come back and hear stuff."
Kelly hailed British musician YUNGBLUD as a "new version" of emo legend Bert, while he heaped praise on Blink-182's Travis Barker's drumming on the track.
He added: "It's me, Bert [McCracken] and YUNGBLUD on one of the songs. It's so hard dude.
"YUNGBLUD sounds like a new version of Bert. Their voices register on the same pitch and with that same ferocity. They can both do raspy, on pitch screams."