Uncontrolled recursion in Qt's QDomDocument serialization (QtXml) lets deeply nested untrusted XML crash the app via stack exhaustion (DoS only).
An application is exposed if it accepts untrusted XML and serializes it through QtXml's QDomDocument. Deeply nested XML can trigger uncontrolled recursion during serialization and exhaust the stack.
The attacker needs a way to supply deeply nested XML that the affected application subsequently serializes using QDomDocument. The described impact is denial of service through an application crash; no other impact is stated.
The issue is described in QDomDocument serialization. The available information does not establish impact for applications that parse untrusted XML without serializing it.
Restrict or reject excessively nested untrusted XML before it reaches QDomDocument serialization, and avoid serializing attacker-controlled DOM documents where possible. This mitigates the stack-exhaustion condition described.