NexGen Energy Ltd.

11/10/2026 | Press release | Distributed by Public on 11/10/2026 05:01

Certification of Interim Filings Full Certificate (Form 6-K)

5.1 Control framework: The control framework the issuer's other certifying officer(s) and I used to design the issuer's ICFR is the Internal control - Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

5.2 N/A

5.3 N/A

6. Reporting changes in ICFR: The issuer has disclosed in its interim MD&A any change in the issuer's ICFR that occurred during the period beginning on July 1, 2026 and ended on September 30, 2026 that has materially affected, or is reasonably likely to materially affect, the issuer's ICFR.

Date: November 9, 2026

"Leigh Curyer"

_______________________

Leigh Curyer

Chief Executive Officer

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