Insufficient data validation in Reader Mode in Google Chrome on iOS prior to 89.0.4389.72 allowed a remote attacker to leak cross-origin data via a crafted HTML page and a malicious server.
https://www.debian.org/security/2021/dsa-4886
https://security.gentoo.org/glsa/202104-08
https://chromereleases.googleblog.com/2021/03/stable-channel-update-for-desktop.html