An_Ign wrote:
https://discussions.apple.com/content/attachment/bb71b469-e8c5-41a6-b819-7f333a15f61c
Hello.
Can I delete these files like “SecUpd2021-003 Catalina.pkg” etc? I’m out of memory on my Mac
because of them as well. I want to download a new update but it needs a lot of GBs.
Will it affect my Mac system? I hope no :(
(sorry for my english, it’s not my native language).
Memory = RAM
Storage = SSD
It seems a bit odd...
From Finder>Go>Go To Folder
/Library/Updates/
I have never seen such an accumulation of pkg files...
(List View in "Big Sur"...)

The SecUpd2021-003 Catalina.pkg link typically downloads a .dmg
https://support.apple.com/kb/DL2075?locale=en_US
You can try reinstalling it and see if it clears up your /Library/Updates/
You can try a Safeboot to clear system cache files
To free up storage—
How to free up storage space on your Mac - Apple Support
https://support.apple.com/en-us/HT206996
User tip: "Other and What Can I Do About It ?"
https://discussions.apple.com/docs/DOC-5142
.