Apostrophe Technologies sanitize-html before 2.3.1 does not properly handle internationalized domain name (IDN) which could allow an attacker to bypass hostname whitelist validation set by the "allowedIframeHostnames" option. Reference: https://github.com/apostrophecms/sanitize-html/pull/458
This issue has been addressed in the following products: Red Hat OpenShift Container Platform 4.8 Via RHSA-2021:2438 https://access.redhat.com/errata/RHSA-2021:2438
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2021-26539
This issue has been addressed in the following products: Red Hat OpenShift Container Platform 4.9 Via RHSA-2021:3759 https://access.redhat.com/errata/RHSA-2021:3759