Kelly Clarkson's ex-husband, Brandon Blackstock, sadly passed away on August 7, 2025, after bravely battling cancer for more than three years. The specific type of cancer was melanoma, a serious form of skin cancer. Additionally, his death certificate revealed that seizures were a significant contributing factor to his passing. He died peacefully at his home in Butte, Montana, surrounded by family. Despite their difficult divorce, Clarkson had been focusing on their children during his illness and showed grace in handling the complex situation. Brandon was also involved romantically with his former assistant after their separation and was building a life with her before his death. The couple had two children together, and Brandon also had children from a previous marriage. His passing has been met with an outpouring of sympathy and respect for his courageous fight against cancer. In summary, what was "wrong" with Kelly Clarkson's husband was that he suffered from malignant melanoma and related health complications, including seizures, which ultimately led to his death at age 48.