Mercusys AC12G (EU) V1 with firmware AC12G(EU)_V1_200909 returns 128 bytes of uninitialized buffer when receiving POST requests without SOAPAction header on UPnP port 1900, exposing internal memory to unauthenticated adjacent network attackers.Referenceshttps://github.com/Tymbark7372/MERCUSYS-AC12G/blob/master/advisories/CVE-2026-36611.md
