Material Event (Form 8-K)

Item 8.01 Other Events.

The Board of Directors of Winchester Bancorp, Inc. (the "Company") has adopted a share repurchase program (the "Share Repurchase Program"), which authorizes the repurchase up to 464,769 shares of the Company's common stock, $0.01 par value per share ("Common Stock"), or approximately 5% of its current outstanding shares of Common Stock. This authority may be exercised from time to time and in such amounts as market conditions warrant, and subject to regulatory considerations.

The timing and actual number of shares repurchased will depend on a variety of factors including price, corporate and regulatory requirements, market conditions, and other corporate liquidity requirements and priorities. The Share Repurchase Program will commence on September 30, 2026, and expire on September 1, 2027, and may be modified, suspended, or discontinued at any time.