What are the file types can not be blocked in SharePoint?

Question

Understanding there is option in SharePoint Central Admin to restrict the file type to be blocked based on web application level.

By default, several standard file extensions are blocked on Microsoft Windows SharePoint Services, including any file extensions that are treated as executable files by Windows Explorer. The file extensions blocked by default are:

ade, adp,app, asa, asp, bas, bat, cdx, cer, chm, class, cmd, com, cpl, crt, csh, dll, exe, fxp, hlp, hta, htr, htw, ida, idc, idq, ins, isp, its, jse, ksh, lnk, mad, maf, mag, mam, maq, mar, mas, mat, mau, mav, maw, mda, mdb, mde, mdt, mdw, mdz, msc, msi, msp, mst, ops, pcd, pif, prf, prg, printer, pst, reg, scf, scr, sct, shb, shs, shtm, shtml, stm, url, vb, vbe, vbs, wsc, wsf, wsh.

Would like to ask what are the file types that can't be blocked in SharePoint, for example, ".aspx".

I will need the list of exception file type and support from the official authority, so to whitelist those exception and justify for the security report.

Answer 1

Hi @Ching Song Lim ,

Would it be convenient for you to tell me whether you are using sharepoint online or sharepoint server?

One thing needs to be clarified, recent improvements in SharePoint in Microsoft 365 and  SharePoint Server 2019 have removed the limitations on types of files that can be added. There are currently no known types of files that cannot be added.

Reference:https://support.microsoft.com/en-us/office/types-of-files-that-cannot-be-added-to-a-list-or-library-30be234d-e551-4c2a-8de8-f8546ffbf5b3

I tested a few of the file types listed in your original post. If the file extension is not set to block, all types of files can be uploaded normally.

I know your question is asking which file types can be uploaded even if they are blocked?

As far as I know, maybe only ".aspx" can be uploaded after being blocked.

Currently there isn't any official documentation describing the list of exception file type. Also I searched internally and externally and no other user has experience with this issue.

If you would like Microsoft to explain the exception file type that cannot be blocked in SharePoint, you can submit new ideas on the SharePoint Feedback Portal .

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