Material Event (Form 8-K)

On January 14, 2026, CompoSecure, Inc. (the "Company") filed with the Securities and Exchange Commission (the "SEC") a prospectus supplement to the prospectus included in the Company's registration statement on Form S-3ASR (File No. 333-292706), filed with the SEC on January 13, 2026 (the "Registration Statement"), covering the resale by certain selling stockholders named therein of 161,034,417 shares of the Company's common stock.

A copy of the legal opinion of Paul, Weiss, Rifkind, Wharton & Garrison LLP relating to the shares is filed herewith as Exhibit 5.1 and is incorporated herein by reference, and is filed with reference to, and is hereby incorporated by reference into, the Registration Statement.