Google has recently reported that Chromium has a security issue - Type confusion in the V8 JavaScript engine - which is reported in a bit more detail here: https://chromereleases.googleblog.com/2022/03/stable-channel-update-for-desktop_25.html. This has been assigned the CVE id CVE-2022-1096.
This effects QtWebEngine as well since it is using Chromium to provide that functionality. Therefore as a result Qt needs to be patched as well to fix this problem. There is no workaround for this so the only solution is to apply the patch.
Solution: Apply the patch or update to Qt 5.15.9, Qt 6.2.5 or Qt 6.3.0.