> CVE-2025-20678: Mediatek Baseband Unbounded Recursion Leading to Stack Overflow During Handling XML Payload

An attacker sending a malformed SIP message over VoLTE to a device with a Mediatek baseband can trigger the vulnerability described here. This report describes an unbounded recursion issue, which leads to stack overflow. (Note: the issue is stack overflow not stack buffer overtflow, i.e. an out-of-bounds write beyond a stack frame’s end). The vulnerability described in this advisory affected a wide range of Mediatek devices. This vulnerability is assigned CVE-2025-20725. Vulnerability Details The XML parser code executes unbounded recursions. In addition, it lacks early checking of the validity of the XML against the expected schema, which might otherwise act as an upper bound for recursion for most XML documents.