Item 1.05 Material Cybersecurity Incidents. As previously disclosed in the Original Report, the Company determined on May 7, 2026 that the Company had experienced a material cybersecurity attack, in which certain data was exfiltrated by an unauthorized party and certain systems were encrypted. Upon initial detection of an intrusion on May 4, 2026, the Company promptly activated its incident response protocols, including proactively taking systems offline globally for containment purposes, notifying law enforcement, and engaging external cyber-forensic experts. Remediation efforts have since progressed, with core enterprise systems restored in addition to critical processes for manufacturing, receiving and shipping restarted at all sites. The Company is now fully operational across its manufacturing, supply chain and commercial sites globally. While the Company’s investigation into the nature and scope of the incident is continuing, including with respect to the extent of the data affected, no unauthorized activity or access is ongoing or has been observed since May 5, 2026. Based on the investigation to date and information currently available, the Company believes that the incident has not had, and is not reasonably likely to have, a material impact on the Company’s 2026 second-quarter and full-year financial guidance. Forward-Looking Statements This Current Report on Form 8-K contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding the Company's expectations regarding future events, financial guidance, actions or performance related to the cybersecurity incident, including the results of the Company’s ongoing investigation thereof and the impact of the cybersecurity incident on the Company, and its financial or operational performance. Forward-looking statements may be identified by words such as "believe," "expect," "intend," "estimate," "plan," "anticipate," "project," "forecast," "guidance," "target," "may," "will," "continue" and similar expressions. These statements are based on current expectations and assumptions and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such forward-looking statements. For additional information regarding these risks as well as other risks, uncertainties and factors that could affect our forward-looking statements, please refer to Part I Item 1A, entitled "Risk Factors," of the Company's most recent Annual Report on Form 10-K and any amendments thereto, as well as the Company's most recently filed Quarterly Reports on Form 10-Q and other filings the Company makes with the Securities and Exchange Commission. Forward-looking statements speak only as of the date of this Current Report on Form 8-K. Except as required by law or regulation, West Pharmaceutical Services, Inc. undertakes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. Item 9.01 Financial Statements and Exhibits. (d) Exhibit No. Description 104 Cover Page Interactive Data File (embedded within the Inline XBRL document). 2 SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Date: May 20, 2026 WEST PHARMACEUTICAL SERVICES, INC. By: /s/ Norman D. Finch Jr. Norman D. Finch Jr. Senior Vice President, General Counsel and Corporate Secretary 3 EXHIBIT INDEX Exhibit No. Description 104 Cover Page Interactive Data File (embedded within the Inline XBRL document). 4