A vulnerability in qt5-qtbase's QDomDocument serialization (QtXml) allows an attacker to cause a denial of service (DoS) via uncontrolled recursion leading to stack exhaustion when processing deeply nested untrusted XML. This issue affects versions prior to 5.15.10-19.oe2403sp3 and has been assigned CVE-2026-11573. A security update fixing this issue is available.