What could cause bubbles to burst if central banks practice yield curve control?

If central banks practice yield curve control (controlling long-term interest rates at a very low level), as real long-term interest rates are structurally negative and the money supply is structurally rising, increasingly large asset price bubbles will appear (in equities, real estate, etc.). So what could cause these bubbles to burst and trigger a financial, banking and economic crisis? No longer a rise in interest rates as in the past, unless central banks abandon yield curve control; A recession, but it can no longer be triggered by a rise in interest rates; Simply the fact that the value of assets becomes too high relative to incomes, which triggers a downturn in asset prices, leading to asset sales and to bubbles bursting.