Material Fact 02/26 - Amendment and Renewal of the Share Buyback Program

CNPJ 76.483.817/0001-20 - NIRE 41300036535 - CVM Registration no. 1431 B3 (CPLE3) / NYSE (ELPC) / LATIBEX (XCOPO)

COPEL ("Company"), in compliance with the applicable norms, including CVM Resolutions No. 44/2021 and 77/2022, hereby informs its shareholders and the market in general that, on the date hereof, the Company's Board of Directors has approved ("BoD May 21, 26"), the amendment and renewal of the current share repurchase program, originally approved on November 25, 2024 ("Program"), as follows:.

1. the Program maintains its purpose focused at the acquisition of shares issued by the Company to be held in treasury, cancelled or sold, without reduction of the amount of the Company's share capital, as well as to meet the requirements of share-based incentive plans;

2. the Company will be able to acquire up to 285,506,846 (two hundred and eighty-five million, five hundred and six thousand, eight hundred and forty-six) additional common shares, that, in addition to the shares currently held in treasury, will correspond to 10.0% of the total number of outstanding shares. For reference purposes, there are currently: (i) 2,982,301,396 (two billion, nine hundred and eighty-two million, three hundred and one thousand, three hundred and ninety-six) common shares outstanding in the market; and

   (ii) 12,723,294 (twelve million, seven hundred and twenty-three thousand, two hundred and ninety-four) common shares held in treasury (considering acquisitions previously made by the Company in the ambit of the Program and the conversion of preferred shares into common shares held on 2025);

3. the term for acquisitions of shares under the Program was renewed for an additional period of up to eighteen

   (18) months, starting on this date, now ending on November 21, 2027;

4. the acquisitions of shares shall be carried out on B3 S.A. - Brasil, Bolsa, Balcão ("B3") at market prices, and the Company's Executive Board shall perform all acts necessary for the implementation of the Program, including, in compliance with the limits set forth in the applicable regulation, defining the timing and quantity of shares to be acquired in a single transaction or in a series of transactions, as well as the acquisition price.

5. the acquisitions shall be limited to the balance of profits for the current fiscal year and available profit and capital reserves, and shall not affect dividend distributions.

6. transactions may be carried out through the intermediation of the following financial institutions: Itaú Corretora de Valores S.A.; BTG Pactual Corretora de Títulos e Valores Mobiliários S.A.; and Morgan Stanley Corretora de Títulos e Valores Mobiliários S.A.

The Company highlights that the terms, conditions and other characteristics of the Program, as required by the CVM regulation, are described in detail in the minutes of the Board of Directors meeting held on May 21, 2026, available for consultation on the websites of the Company (https://ri.copel.com), the Comissão de Valores Mobiliários (https://www.gov.br/cvmr) and B3 (https://www.b3.com.br).

Curitiba, May 21 2026

Vice President of Finance and Investor Relations

For further information, please contact the Investor Relations team: ri@copel.com or (41) 3331-4011