Core Natural Resources, Inc.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On August 18, 2026, as part of its long-term succession process, the Board of Directors (the “Board”) of Core Natural Resources, Inc. (the “Company”) appointed Nathan Tucker to serve as the Company’s Senior Vice President and Chief Financial Officer, effective immediately, taking over the Chief Financial Officer role from Mitesh Thakkar, who will continue to serve as President of the Company and is assuming an expanded role with day-to-day responsibility for the Company’s primary operating functions, including operations, marketing, logistics, and long-term strategy. Mr. Tucker, age 39, has served as the Company’s vice president of finance since the Company’s formation in January 2025 via the merger of CONSOL Energy Inc. (“CONSOL”) and Arch Resources, Inc. He previously served as director of finance and investor relations for CONSOL from 2020 until January 2025 after joining CONSOL in 2010. In connection with Mr. Tucker’s appointment, the Board approved a new compensation package for Mr. Tucker to increase his annual base salary to $400,000, his target short-term incentive compensation opportunity to 65% of his annual base salary, and his long-term incentive compensation opportunity to 125% of his annual base salary. Mr. Tucker also received a severance agreement (the “Severance Agreement”) in connection with his appointment, which contains substantially the same terms and conditions as the severance agreements entered into with the Company’s other executive officers. The foregoing description of the Severance Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the form severance agreement, which was filed as Exhibit 10.72 with the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

Item 7.01 Regulation FD Disclosure. On August 19, 2026, the Company issued a press release announcing its executive succession plan and the appointment of Mr. Tucker as the Company’s Senior Vice President and Chief Financial Officer, which is furnished as Exhibit 99.1 hereto and is incorporated herein by reference. The information contained in this Item 7.01 and Exhibit 99.1 shall be considered “furnished” and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, nor shall it be deemed incorporated by reference into any reports or filings with the Securities and Exchange Commission, whether made before or after the date hereof, except as expressly set forth by specific reference in such a filing.