UMG and Sony File Second Suit Against Suno, Alleging V6 Models Infringe via 'Poisoned Tree' Training

Key points

• Universal Music Group and Sony Music Entertainment filed a new 45-page lawsuit against Suno on September 18, 2026, in Boston federal court.
• The complaint alleges Suno's v6 models were trained on outputs from previous models (v4 through v5.5) that were built on 60,202 unlicensed recordings from the labels.
• The labels argue that training a new model on infringing outputs does not erase liability but 'launders' the infringement, calling v6 'the fruit of the same poisoned tree.'
• Suno states that v6 was trained on content licensed from Warner Music Group, BMG, and Believe, as well as user interactions and preference signals, and denies the allegations.
• The labels seek statutory damages up to $150,000 per work, potentially totaling over $9 billion, plus up to $150 million for circumventing YouTube's anti-downloading technology.
• This is the second major lawsuit from UMG and Sony against Suno, following an initial case filed in June 2024 that covered 560 works.

Background

This lawsuit follows a series of legal actions against Suno in 2026, including a class-action suit by musicians like Jason Isbell over AI-generated likenesses and a $1 billion suit by Round Hill Music. Suno had previously settled with Warner Music Group in November 2025 and signed deals with BMG and Believe in 2026 to license content for its v6 models. The labels argue these deals prove a market exists for licensing, undermining Suno's fair use defense. The initial lawsuit by UMG and Sony in June 2024 covered 560 works, but a judge refused to add 61,026 more works, prompting this new filing.

How outlets are covering it

Music Business Worldwide and Variety emphasize the labels' argument that v6 is tainted by prior infringing models and that Suno's licensing deals with other labels undermine its fair use defense. Gizmodo highlights Suno's response, which claims v6 was trained on licensed content and user data, and notes that Suno's previous models were exposed in a data breach earlier in 2026. Axios provides a broader context of AI-generated music driving legal frenzy, but does not detail the specific claims in this lawsuit. The outlets agree on the core facts of the lawsuit but differ in emphasis, with some focusing on the legal strategy and others on Suno's defense.

Why it matters

This lawsuit could set a precedent for how AI models trained on outputs of previous models are treated under copyright law. If the labels succeed, it could force AI companies to ensure that all training data is licensed, even if it is derived from user interactions or previous model outputs. The potential damages of over $9 billion could also have significant financial implications for Suno and other AI music platforms. The case also highlights the tension between AI innovation and copyright protection in the music industry.

What to watch

The next step is likely a court hearing on the motion to dismiss or a summary judgment motion. The labels will need to prove that v6 was trained on outputs from infringing models, while Suno will argue that v6 was trained on licensed content and user data. The outcome of this case could influence other AI copyright lawsuits in the music industry and potentially lead to new regulations or guidelines for AI training data.