Views Board's Decision to Replace Doss as Misguided, Ill-timed, and Done Without Proper Diligence Believes that Chairman Phil Martens Wields Outsized Influence over GPK's Board, has Jeopardized Shareholder Value, and Should Resign Encourages Shareholders with Similar Concerns to Voice Them Eminence to Evaluate All Options to Ensure Board Is Comprised of Individuals Who Are Committed to Protecting Shareholder Value NEW YORK , Dec. 19, 2025 /PRNewswire/ -- Eminence Capital, LP ("Eminence"), a private investment firm that beneficially owns approximately 4.2% of Graphic Packaging Holding Company (NYSE: GPK) ("GPK" or the "Company") today announced it sent a letter to GPK's Board of Directors (the "Board") on December 15, 2025 following the Board's seemingly inexplicable and clearly rushed decision to replace long-standing CEO Mike Doss with Robbert Reitbroek. Mr. Reitbroek's only prior stint as a public company CEO was an unmitigated disaster for investors that ended in his termination just weeks ago and led to numerous class action complaints and a derivative action launched against him, his previous employer, and certain other related defendants.