Mercku hasn't responded to a security researcher for more than a year and appears that its support portal was hacked
The researcher has now published details about a bunch of bugs that allow router takeovers
nullvoid.me - Merck'd-U!
Critical flaws discovered in Mercku routers, specifically the M6a model, that could allow attackers to achieve remote code execution with minimal effort.
nullvoid.me (blog.nullvoid.me)
