Material event report (decision to redeem own convertible bonds early)

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Material Event Report (Decision to Redeem Own Convertible Bonds Before Maturity) 6.0

CS Co., Ltd.

Material Event Report / Exchange Reporting Obligation To the Financial Services Commission / Korea Exchange August 28, 2026

Company name: CS Co., Ltd. Representative Directors: Choi Gyu-hun, Kim Tae-yeon Head office address: 8th Floor, Winstechnet-dong, 15 Pangyo-ro 228beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do (Phone) 031-622-3200 (Website) http://www.cs-holdings.co.kr Preparer: (Title) Head of Management Support Division (Name) Han Sang-hyeok (Phone) 031-622-3200

Decision to Redeem Own Convertible Bonds Before Maturity

1. Type of bonds: Series 6, Unregistered interest-bearing unsecured private-placement convertible bonds 2. Bond issuance date: 2026-05-29 3. Bond issuance method: Private placement 4. Bond maturity date: 2029-05-29 5. Total face value (electronically registered) of the bonds (KRW): 5,000,000,000 6. Face value (electronically registered) of bonds subject to acquisition (KRW): 5,000,000,000 7. Date of acquisition decision: 2026-08-28 8. Acquisition amount: Amount (KRW) 5,024,547,562; Basis of calculation: Principal and interest; Payment date (scheduled): 2026-08-28; Source of acquisition funds: Own funds 9. Acquisition method: Over-the-counter purchase 10. Reason for acquisition before maturity: Acquisition of bonds before maturity following the occurrence of a cause for loss of the benefit of time (designation as an administrative issue) 11. Future handling plan: To be decided through a future board of directors' resolution 12. Matters relating to conversion: Conversion ratio (%) 100; Conversion price as of the reporting date (KRW/share) 3,424; Type of shares to be issued upon conversion: CS Co., Ltd. registered common shares; Number of shares 1,460,280; Ratio to total shares outstanding (%) 13.08; Conversion request period: from 2027-05-29 to 2029-04-29 13. Remaining face value (electronically registered) of the bonds after acquisition (KRW): - 14. Whether subject to reporting to the Fair Trade Commission: Not applicable 15. Other matters for reference in investment decisions: The Company was designated as an administrative issue on the KOSDAQ market, and this is a case in which bondholders requested early redemption due to the occurrence of a cause for loss of the benefit of time on the convertible bonds, and the Company accordingly acquired the bonds. The early acquisition procedure for the early redemption request amount of KRW 5,000,000,000 has been completed.

[Matters Concerning the Sellers] Seller name; Relationship with the company or largest shareholder; Selection process; Transaction history and plans within 6 months before/after the acquisition decision; Face value of bonds sold (KRW); Note

KB Securities Co., Ltd.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 800,000,000 Shinhan Investment Corp.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 700,000,000 NH Investment & Securities Co., Ltd.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 790,000,000 KB Securities Co., Ltd.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 710,000,000 Korea Investment & Securities Co., Ltd.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 370,000,000 Korea Investment & Securities Co., Ltd.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 340,000,000 Samsung Securities Co., Ltd.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 170,000,000 Samsung Securities Co., Ltd.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 120,000,000 KB Securities Co., Ltd.: Relationship - creditor of these bonds; Face value of bonds sold (KRW) 500,000,000 Park O Woo (name partially masked in the original filing, as stated in the filing): Relationship - creditor of these bonds; Face value of bonds sold (KRW) 500,000,000