brave-browser: Google Project Zero website causes high Brave CPU usage

Description

When visiting the Google Project Zero website, it causes high Brave CPU usage (in both Brave Stable and Nightly).

The issue occurs on a clean Brave install, with default browser settings and no third-party extensions installed.

Closing the browser window does not make the CPU usage return to normal – Brave needs to be forcibly closed from the Windows Task Manager.

In Edge and Chrome, the CPU usage is normal.

In a Brave “Private Window”, the CPU usage is normal.

Steps to Reproduce

1) Open Brave.

2) Go to the below link:

https://googleprojectzero.blogspot.com/2023/03/multiple-internet-to-baseband-remote-rce.html

3) Observe the CPU usage in Windows Task Manager. (High)

4) Close Brave.

5) Observe the CPU usage in Windows Task Manager. (Still high)

6) Close Brave (End Task) via the Windows Task Manager.

7) Observe the CPU usage in Windows Task Manager. (Back to normal)

Actual result:

The Brave CPU usage is too high (around 50%).

Screenshots:

Brave Stable – before opening Project Zero link (OK):

Brave Stable – after opening Project Zero link (Not OK):

Brave Nightly – after opening Project Zero link (Not OK):

Chrome – after opening Project Zero link (OK):

Edge – after opening Project Zero link (OK):

Expected result:

The Brave CPU usage should be normal (<5%).

Screenshot:

Brave Stable (in Private Window) – after opening Project Zero link (OK):

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave:    1.49.120 Chromium: 111.0.5563.64 (Official Build) (64-bit) 
Revision: c710e93d5b63b7095afe8c2c17df34408078439d-refs/branch-heads/5563@{#995}
OS:       Windows 10 Version 22H2 (Build 19045.2728)

Brave:    1.51.39 Chromium: 111.0.5563.64 (Official Build) nightly (64-bit) 
Revision: c710e93d5b63b7095afe8c2c17df34408078439d-refs/branch-heads/5563@{#995}
OS:       Windows 10 Version 2004 (Build 19041.2728)

Version/Channel Information:

• Can you reproduce this issue with the current release? Yes
• Can you reproduce this issue with the beta channel? Not tried
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? No
• Does the issue resolve itself when disabling Brave Rewards? No
• Is the issue reproducible on the latest version of Chrome? No