Windows 11 Update KB5065426(26100.6584) Size 88.5GB in Vulnerability scan results - Needs fixing!

Hi,

Has anybody tried to install the latest update from Windows version mentioned in the title?

I have never downloaded an update this size, even the win10-11 transition was not this big, if I'm not wrong..I was apprehensive of downloading this update because of the size, and its repercussions…This is probably a bug which is displaying the incorrect size.

Can the developers pls fix this bug so future updates are not hampered?

Also, security widget is not showing on my desktop since 2 days.

Find more posts tagged with

Accepted answers

All comments

Alexandru_BD

@camarie I remember seeing this before, I think 88.5 GB is unreal..
But that doesn't actually refer to the update size, right? I mean, it says there "maximum size".

CatalinC.RO

Hello!

That notification isn’t new — it usually appears when there are operating system updates available. However, I think the mention of 88.5 GB is quite misleading for users. It would be great if the notification could be reconsidered or clarified in the future.

camarie

The maximum download size does not represent the whole necessary size of the content to be downloaded. This depends on the configuration of the system to be updated.
For example, if one updates from 23H2 to 24H2, it might be a couple of gigabytes. But if one updates 21H2 to 24H2, it might go 21H2 > 22H2 > 23H2 > 24H2, which may or may not require the subsequent apply of large updates.

I'm not saying this is the case, but this is what Microsoft themselves state on the internal object download maximum size (IUpdate represents a Windows Update description item, and MaxDownloadSize is the property we display):

"However, the MaxDownloadSize property is not always downloaded. The MaxDownloadSize property is downloaded based on the configuration of the computer that receives the update."

The information we display is based on the information provided by the Microsoft Windows Update client (namely wuapi.dll).

For example, this is what my Windows 11 machine displays using a simple VB ******:

…
updates found: 9
…
update 6 of 9
Title : 2025-08 Cumulative Update for Windows 11 Version 23H2 for x64-based Systems (KB5063875)
Min size : 0 (0 MB)
Max size : 137665335836 (131287.9 MB)
Installed: True
…
update 9 of 9
Title : NVIDIA - Display - 32.0.15.7344
Min size : 0 (0 MB)
Max size : 1081073355 (1030.99 MB)
Installed: False

As you can see, the NVIDIA display driver update (not installed) is 1.04GB itself; Cumulative 23H2 update is 131287.9 MB, which is roughly 128 GB (already installed).

I tend to believe the numbers reported by the Windows Update client, even if they are large. Of course, I do not rule out a bug, but unless proven somehow, I cannot say this is a bug yet.

Flexx

To add here, according to the Microsoft Update Catalog, the size of KB5065426 is between 3–4 GB. Below is the link to it:

https://www.catalog.update.microsoft.com/Search.aspx?q=kb5065426

Regards

camarie

True. This is only the size of the update package itself. In my experience, even updates with very large maximum download size reported are never reaching this size. But, again, this is the estimated size reported by the Windows Update itself.