I used to feel sorry for Macrium, AOMEI, and Veeam. But they need to hire a Windows security consultant.
Before the whole CA 2023 migration, Windows boot file security was rather weak. If someone reported a boot file vulnerability to MS, they would quietly fix the bug and issue a new boot file. The problem was there wasn't a strong effort to make sure everyone was running the latest file. Someone could be running an older version and not realize it.
How do you force everyone to use the latest boot file?
Every month, Windows Update
might drop a new boot file. This month (April 2026), they closed two security holes related to boot manager. A newer version of the boot file was released in sync with a new SVN number. The SVN is a version number which controls which boot file is allowed to work, since every boot file knows its own SVN number.
After your UEFI gets updated to a higher SVN, older boot files cannot be used. This takes care of Windows system security.
That doesn't help your bootable USB drive. It has an older boot file, with the wrong SVN. The solution is very simple, just copy the same boot file that's on Windows under the System32\SecureBootUpdates folder.
Backup companies like Macrium, AOMEI, and Veeam are trapped like it's 2023. They keep asking users for the Windows ADK, which has an outdated copy of the boot file. The ADK is provided to IT admins so they can built custom Windows install images. But it doesn't change as quickly as the Monthly Updates. If you're using the ADK, it's already two (three?) versions out of date. The SVN has gone from 2.0 -> 5.0 -> 7.0 -> 8.0.
MS has patched the boot manager a few times to make sure the reported security holes are gone. So if you're in the new Secure Boot world, they should stop trying to require the ADK. The current boot file will be included with whatever version of Windows you're on.
Some vendors allow you to use the WinRE method, which is better. WinRE shares the same boot file as normal Windows. So that's much better than depending on the ADK. But we are still left with one annoying problem...
Your backup vendor doesn't bother checking with MS if a new boot file arrived. If that happens, you need to replace the boot file on that USB drive again. They should come up with a method which alerts users that "a new boot file was released", and have the backup tool refresh your recovery drive for you. But those companies are acting like it's 2023.
