From Microsoft, "Action Recommended: Before 10/1/2026, convert your existing Publisher files to PDF or Word format. After this date, you will no longer be able to open or edit these files with Microsoft Publisher."

https://support.microsoft.com/en-us/office/microsoft-publisher-will-no-longer-be-supported-after-october-2026-ee6302a2-4bc7-4841-babf-8e9be3acbfd7#:~:text=How%20will%20this%20affect%20you,Publisher%20from%20that%20date%20forward.

Affecting all Publisher titles. We will certainly check back on this to see if Microsoft can actually discontinue use of an application people have relied on for years.