8-K

/s/ Daniel S. Fishbein

Daniel S. Fishbein

Date: August 17, 2026

Executive Vice President, General Counsel and Secretary

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): August 14, 2026

GRAPHIC PACKAGING HOLDING COMPANY

(Exact name of registrant as specified in its charter)

Delaware

001-33988

26-0405422

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

1500 Riveredge Parkway

Atlanta, Georgia 30328

(Address of principal executive offices)

(770) 240-7200

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class

Trading

Symbol

Name of Each Exchange

on Which Registered

Common Stock, $0.01 par value per share

GPK

New York Stock Exchange

☐ Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

Item 8.01.

Other Events.

On August 14, 2026, a purported stockholder of Graphic Packaging Holding Company (“GPHC”) filed a derivative lawsuit against GPHC and certain current and former officers and directors as individual defendants (the “August 2026 Derivative Action”). The August 2026 Derivative Action asserts claims for violations of federal securities laws and for breach of fiduciary duty, aiding and abetting breach of fiduciary duty, waste of corporate assets and unjust enrichment. The allegations set forth and relief sought in the August 2026 Derivative Action are substantially similar to the allegations and relief sought in the June 2026 derivative action filed against GPHC and certain current and former officers and directors as previously disclosed in GPHC’s Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2026. GPHC intends to vigorously defend against the claims in the August 2026 Derivative Action.

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