Mr. Kirby Renton reports

NIOBIUMX MINING INC. APPOINTS ATHABASCA BASIN DISCOVERY GEOLOGIST ERIK SEHN TO BOARD OF DIRECTORS

Niobiumx Mining Inc. has appointed Erik Sehn, PGeo, as a director of the company, effective Sept. 17, 2026.

Background

Mr. Sehn is a professional geologist with nearly 10 years of experience in mineral exploration, project management and the advancement of exploration projects in Canada. He has served as vice-president, exploration, of F4 Uranium Corp. since September, 2025, and previously served as senior project manager with F3 Uranium Corp., where he held senior technical and management roles, and contributed to the discovery and advancement of the JR zone and the Tetra zone at the Patterson Lake North project in the Athabasca basin of Saskatchewan. His earlier work in the Athabasca basin included the Triple R deposit. He brings experience in exploration strategy, drill program design and execution, geological interpretation, technical team leadership, and the evaluation and advancement of early stage mineral exploration projects.

Shipshaw and the program

The Shipshaw property comprises 48 mineral claims totalling approximately 2,686 hectares in the Saint-Honore carbonatite district of Quebec. The nearest claim boundary lies less than two kilometres from the mining-lease boundary of the producing Niobec mine. The most recent geophysical survey in the assessment record is a heliborne magnetic survey flown in May, 2010. The company's current technical report, prepared by Bertrand Brassard, MSc, PGeo, with an effective date of Feb. 17, 2026, and available under the company's profile on SEDAR+, recommends a two-phase program: relocation and reassay of historical drill core for total rare-earth elements together with magnetic modelling, followed by drill testing. Mr. Sehn will advise the board on the design and execution of that program. The Shipshaw property does not host a mineral resource or mineral reserve estimate.

"Erik has taken targets from geophysics through drilling to discovery in the Athabasca basin. That is the sequence in front of us at Shipshaw: a carbonatite system with no airborne geophysics in more than 15 years, a technical report that tells us where to start and now a director who has run that program through to a discovery. We welcome him to the board," said Kirby Renton, president and chief executive officer.

The company also announces that Dr. Terrance G. Owen has resigned as a director of the company, effective Sept. 17, 2026. Dr. Owen served as an independent director through the acquisition of the Shipshaw property and the company's transition from Arctic Fox Lithium Corp. to Niobiumx Mining. He brought more than 30 years of public company, corporate finance and capital markets experience to the board, and his judgment and steady counsel were valued throughout. The board thanks Dr. Owen for his service and wishes him every success.

Qualified person

The scientific and technical information in this news release has been reviewed and approved by Babak V. Azar, MSc, PGeo (OGQ No. 10876), a qualified person as defined by National Instrument 43-101.

About Niobiumx Mining Inc.

Niobiumx Mining is a Canadian mineral exploration company focused on niobium and rare-earth elements. The company's principal asset is the Shipshaw property, a package of 48 mineral claims totalling approximately 2,686 hectares in the Saguenay region of Quebec, situated within the Saguenay Graben of the Grenville Geological province, and characterized by a swarm of carbonatite and lamprophyre dikes. The Shipshaw property does not host a mineral resource or mineral reserve estimate.

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