It’s rather awkward when you buy a piece of hardware like a sketchy router to make a video about its hidden admin password backdoor – known as CVE-2026-11405 – only to discover that you bought the wrong Tenda router, namely the AC10V6 model. After making this mistake, [Low Level] did the only reasonable thing one ought to do in this case, and try to find an exploit in this ‘wrong’ router as well.
The obvious start here is to do the same as with the other exploit, in that you download a firmware image from the manufacturer’s website, then pluck it apart using binwalk to do an initial check for juicy files. After that tools like Ghidra can be used to do a more in-depth analysis of any binary files, with a special focus on things like user-facing elements like login screen, as input validation will likely forever remain the number one type of exploited CVE.
One major change that Tenda made here was to encrypt the firmware image, which seemed suspicious. With that easy path blocked, the research of others on different Tenda routers was looked at, including the AC20 with the fascinating Telnet exploit in the form of CVE-2025-9090 where merely poking a file on the device turned on the Telnet service. This left the minor issue of finding a password to log into said Telnet session.

This is where CVE-2025-52054 comes in handy, as this explains how to calculate the root password of a Tenda router using a static string and the last two octets of the device’s MAC address. The unfortunate aspect here is that this static string is unknown for this particular router, and the AC8 version did not work. Luckily, for some unknown reason Tenda did decide that they had to print this secret information to the serial output, ergo it was time to probe the UART pins on the router’s guts.
One hard reset later and the console output on these UART pins happily showed that the password pre-Base64 encoding was 9cUFeUZC_125700. Mashing in the Base64-encoded string in the Telnet login gave root access and completed the first step of the whole fun, as now [Low Level] also had access to the decrypted firmware including the decryption keys for the previously safely encrypted firmware image.
There will be a blog post published with likely the keys and other details after clearing it with [Low Level]’s lawyer, but even at this point it’s truly a tragedy of CVEs on the side of Tenda that led to this outcome. If you ever needed a reason not to let friends use Tenda routers, this has got to be another good reason.










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