Winbond Resolves to Increase Capital in Subsidiary Winbond Electronics Malaysia Sdn. Bhd. (WEM)

1. Name and nature of the subject matter (if preferred shares, specify issuance terms such as dividend rate): Equity of Winbond Electronics Malaysia Sdn. Bhd. (WEM)

2. Date on which the event occurred: 115/6/12 ~ 115/6/12

3. Date of board approval: June 12, 2026

4. Other approval dates: Not applicable

5. Transaction quantity, unit price, and total transaction amount: Number of units: 430 million shares Unit price: RM1 Total transaction amount: RM430 million

6. Counterparty and its relationship with the company (if the counterparty is an individual and not a related party, name disclosure may be omitted): Counterparty: Winbond Electronics Malaysia Sdn. Bhd. (WEM) Relationship with the company: 100%-owned subsidiary

7. If the counterparty is a related party, state the reason for selecting the related party as the transaction party, previous transferor, relationship among the previous transferor, the company, and the counterparty, previous transfer date, and transfer amount: Reason for selecting related party: WEM is a 100%-owned subsidiary, and the capital increase is to meet its funding needs Previous transferor, relationships, previous transfer date, and amount: Not applicable

8. If the ownership of the subject matter was held by a related party of the company within the past five years, disclose the related party’s acquisition and disposal dates, price, and relationship with the company at the time: Not applicable

9. Matters related to the disposal of receivables (including types of collateral attached to disposed receivables; if receivables from related parties are disposed, disclose the related party’s name and book value): Not applicable

10. Gain (or loss) from disposal (not applicable for acquisition of securities) (if previously deferred, provide a table explaining recognition): Not applicable

11. Delivery or payment terms (including payment periods and amounts), contractual restrictions, and other important agreements: Cash injections in stages within the total capital increase amount; no contractual restrictions or other important agreements

12. Decision-making method for this transaction, reference basis for price determination, and decision-making unit: Board resolution

13. Net asset value per share of the securities-issuing company (for acquisition or disposal of securities): Not applicable

14. Cumulative number, amount, ownership percentage, and rights restrictions (e.g., pledge status) of the securities (including this transaction) held to date: Cumulative number: 430,000,001 shares Cumulative amount: RM430,000,001 Ownership percentage: 100% Rights restrictions: None

15. Proportion of securities investments (including this transaction) under Article 3 of the “Regulations Governing the Acquisition or Disposition of Assets by Publicly Issued Companies” to total assets and equity attributable to owners of the parent in the company’s latest financial statements, and the amount of working capital in the latest financial statements (Note 2): Percentage of total assets: 25.5% Percentage of equity attributable to owners of the parent: 39.8% Working capital in latest financial statements: NT$14,242,402 thousand

16. Broker and brokerage fees: Not applicable

17. Specific purpose or use of the acquisition or disposal: To meet WEM’s operational status and funding needs

18. Dissenting directors’ opinions on this transaction: None

19. Whether this transaction is a related-party transaction: Yes

20. Date of auditor’s approval or audit committee’s consent: June 12, 2026

21. Whether the accountant issued a non-reasonable opinion on this transaction: Not applicable

22. Name of accounting firm: Not applicable

23. Name of accountant: Not applicable

24. Accountant’s license number: Not applicable

25. Whether this involves a change in business model: No

26. Explanation of business model change: Not applicable

27. Transaction status with the counterparty in the past year and expected in the next year: Winbond Electronics Malaysia Sdn. Bhd. (WEM) was established on April 20, 2026, with an initial capital of RM1; phased capital injections will be made within the total capital increase amount

28. Source of funds: Internal funds

29. Previous date of material information disclosure on the same event: Not applicable

30. Other explanatory matters: Exchange rate between MYR and NTD is estimated at 7.9