There are 2 open security issues in buster.
You can find information about how to handle this issue in the security team's documentation.
commit 3b4d53a9b419f993afcd9b760720728c1c9602eb Author: Lu Yaning <email@example.com> Date: Mon Sep 13 11:21:18 2021 +0800 Backport upstream patch to fix recursion crash commit fde9dd856e4bf379ec3ac1e411870305433fba1f Author: Debian Janitor <firstname.lastname@example.org> Date: Fri Aug 27 23:06:45 2021 +0000 Apply multi-arch hints. + qtbase5-doc, qtbase5-doc-dev, qtbase5-doc-html: Add Multi-Arch: foreign. Changes-By: apply-multiarch-hints