Tesla Wall Connector bootloader bypasses the firmware downgrade ratchet

5/15/2026 at 1:03:09 AM

PSA: If your wall connector loses wifi, it'll just throw your charging schedules out the window and turn on/off sporadically. This is especially noteworthy if you have Time of Use billing :| SET THE TIMER ON THE CAR DIRECTLY!

by thejazzman

5/15/2026 at 5:28:22 AM

It also fits the broader theme here: too much important behavior seems to live in the "application layer" of the charger, while the more durable source of truth is elsewhere.

by eleveriven

5/15/2026 at 2:14:15 AM

I spent an hour yesterday getting the wall connector back on my wifi. Apparently last October when I added wifi 7 access points my network started working in WPA2/WPA3 mode and the wall connector wasn’t compatible with that. Ended up having to create a second SSID with WPA2 only support to get it back online.

Supposedly the newest update fixes that, but I haven’t taken the time to test that out.

But WiFi is shocking my fragile on these wall connectors, I’ve had a lot of trouble keeping it connected to my home network over the years.

by rblatz

5/15/2026 at 3:34:36 AM

or, use Home Assistant to handle your charging schedules.

by a10c

5/15/2026 at 1:19:20 AM

>SET THE TIMER ON THE CAR DIRECTLY!

This would open up a lot of issues to get away with not paying and charging for free.

by compounding_it

5/15/2026 at 1:24:32 AM

Your comment makes no sense. The tesla wall connector is a home charging port you install in your garage.

by m463

5/15/2026 at 5:30:01 AM

I knew this is about wall charger at home but I assumed ‘time of use billing’ was some kind of billing system for the charger that’s implemented.

by compounding_it

5/15/2026 at 9:53:22 AM

That's done on the property's electricity smart meter.

by pjc50

5/15/2026 at 6:22:57 AM

some people have variable electrical tariffs, so electrical use in the middle of the night is usually much much cheaper than the middle of the day.

by lexicality

5/15/2026 at 6:46:24 AM

Why use Tesla wall connector in a first place and not just the standard nema/dryer outlet with the Tesla cord/charger? It seems like people are overpaying for nothing.

by cryptoegorophy

5/15/2026 at 7:59:22 AM

I can do 48A @ 240V with my wall connector. It's also very convenient.

by tenuousemphasis

5/14/2026 at 11:08:10 PM

I hate the gen 3 wall connector.

It creates a wifi access point in your garage that you cannot turn off:

  TeslaWallConnector_<unique-id>

some people were able to downgrade their firmware to a version that didn't do that, but i guess this article shows telsa got rid of that ability.

I would love to be able to hack any firmware to disable that.

I also read that a connected tesla car can force an over-the-air firmware update maybe through the charging cable or wifi, but I haven't verified that.

by m463

5/15/2026 at 12:26:44 AM

The SSID stops broadcasting after the unit is commissioned, unless you're using power sharing between multiple units. In that case the SSID is used for the units to communicate.

by ralph84

5/15/2026 at 12:36:42 AM

by commissioned you mean "connect it to your home wifi and let it talk to tesla"? (i won't do that)

because it hasn't gone away after configuring the setup stuff (amps, etc)

by m463

5/15/2026 at 12:54:42 AM

Mine did

by Rohansi

5/15/2026 at 12:58:05 AM

And make sure the firmware is up to date. Mine is at 26.2.2.

by ralph84

5/15/2026 at 12:10:52 AM

Thank you. This information is not listed anywhere and I am currently getting quotes for solar panel build.

by iugtmkbdfil834

5/14/2026 at 11:41:05 PM

Repeat after me:

An owner voluntarily downgrading firmware to gain control of your hardware IS NOT A HACK.

And if an adversary is doing this, then they have already breached yoir physical security.

by mystraline

5/15/2026 at 6:29:46 AM

It clearly seems people have different meanings to the word, then.

For example, if I am able to gain root access to a WiFi access point I own, even though the vendor has tried to prevent it, then yes, I would call it a hack. To me, it doesn't matter why or who is doing the steps.

In fact, I believe I have never before heard someone combine the meaning of the word to be related to the ownership of the device being hacked.

I suspect the number of people understanding the word in your way is a minority. Redefining terms doesn't help build mutual understanding: here we are taking a word some think has negative connotations and then remove the thing they think should be cool and ok, and then suggest that this is actually the real meaning of the word. Personally I don't think this is how words should be wielded.

by _flux

5/15/2026 at 9:12:52 AM

> For example, if I am able to gain root access to a WiFi access point I own, even though the vendor has tried to prevent it, then yes, I would call it a hack.

Yep. The owner of the device can sue you.

by oneshtein

5/15/2026 at 5:03:50 AM

This exploit is delivered through the charging cable to the wall box. These wall boxes are sometimes intentionally located in public spaces with the intent of allowing public charging, and Tesla has features specifically for that use case, so that cable is absolutely expected to be plugged in to untrusted vehicles.

by wolrah

5/15/2026 at 2:54:03 AM

It's a car the charging port is a viable physical perimeter, letting people inject code at the pump is a risk of design, not user error.

by abofh

5/15/2026 at 4:44:55 AM

I thought the same thing. How white hat do you have to be to consider ineffective DRM a vulnerability?

by zelon88

5/15/2026 at 12:11:32 AM

Eh, that’s a bad generalization. defense in depth is a thing and there are many cases where you’d want to protect against attackers with physical access

by kube-system

5/15/2026 at 5:36:12 AM

This isn't designed to stop attackers with physical access. This is designed to stop casual tinkerers and shade tree mechanics.

You know what isn't vulnerable? A "dumb" offline charger. You know what doesn't make any money or turn the consumer into another product? A "dumb" offline charger.

If it were about physical security, the suggested fix would be to remove the communication from the port entirely.

Companies shouldn't get to make something simple and secure into something inherently insecure and then iterate security into it. Like drive by wire steering, or brakes. Nobody asked for these things and if you ask ANYONE who works on, builds, or actually enjoys cars the consensus is NOBODY wants it.

But there are enough sophomoric, pedestrian car owners out there who gawk at the senseless overdeployment of technology and think "this is so convinient" and don't see it as 1) regulatory barrier building and gatekeeping 2) enabling vendor lock in 3) overcoming right to repair legislation. So the knowledgeable and enthusiastic voices of reason who care about cars get drowned out by the hoard of pedestrian geeks who couldn't imagine operating a car without at least a 16 inch touchscreen.

In security, the best defense is not introducing a vulnerability at all. There is value in having less code. For example, if your PaaS doesn't collect user SSNs... then it can't lose SSNs in a breach.

The question here should not be "why is this not secure." The question should be "why does this even need to be secure in the first place?" We have a very simple task to do and we've complicated it so much we've introduced vulnerability that didn't exist previously.

by zelon88

5/15/2026 at 4:03:54 AM

Any system where your defense in depth involves UDS is pretty much guaranteed to be broken though.

by AlotOfReading

5/15/2026 at 2:00:54 AM

They shouldn’t be able to do it through the charging cable though lol

by pram

5/15/2026 at 12:14:41 AM

Arguably it’s a crack. A good one, though.

by taneq

5/15/2026 at 3:02:07 AM

I mean its still technically hacking, but not all hacking is bad/illegal.

by aussieguy1234

5/14/2026 at 10:39:33 PM

Why would I want to hack the bootloader for a wall charger? Asking for a friend

by 486sx33

5/14/2026 at 10:53:41 PM

You can bypass vehicle restrictions. You could potentially then use it for J1772-compatible EVs (like a Chevy Bolt or Nissan Leaf)

Or just for the spirit of actually owning the shit you pay for.

by culi

5/14/2026 at 11:16:41 PM

I don't think there are any restrictions. I think j1772 might just work with an adapter (adapt from the nacs plug to the j1772 plug)

I thought tesla even made a j1772 native wall connector.

by m463

5/15/2026 at 2:34:20 AM

There are some restrictions.

I had the foolish idea of installing a Tesla charger at home to charge my Bolt. I’ve been unable to ever use it.

The wall charger works fine with Teslas. My car and adapter charge fine at Tesla superchargers.

But the home Tesla charger refuses to charge my Bolt. (Yes I disabled vehicle restrictions and tried all sorts of combinations of settings for weeks before giving up. Tesla support was useless of course)

Restriction or bug, same difference.

by mprime1

5/15/2026 at 7:37:09 AM

Really gross. I have a gen 1 charger and it's dumb as bricks. Basically just a giant relay.

I guess I could see why you might want to restrict who can use your charger, but I really prefer the "dumb as bricks" version I currently have.

by cogman10

5/14/2026 at 11:35:32 PM

Can confirm. I've used an adapter to charge 2 different non-Tesla cars off my wall connector.

by akerl_

5/14/2026 at 11:52:52 PM

I use my Gen 1 Tesla Wall Connectors to charge my NACS-native Lucid Gravity.

by adamsb6

5/15/2026 at 12:11:59 AM

What vehicle restrictions? This is for the Tesla home charger, not Superchargers.

by decimalenough

5/15/2026 at 3:00:11 AM

Older models are locked to Tesla vehicles. Tesla has regional restrictions in many parts of the world.

You also never know when there could be another update and your region becomes one of those that has these restrictions.

by culi

5/15/2026 at 1:54:44 AM

Exactly. Charge both my Tesla and my leaf with mine.

by brianwawok

5/15/2026 at 3:12:46 AM

Some don't support j1772 adapters with non Tesla vehicles

by Rebelgecko

5/14/2026 at 11:34:52 PM

[dead]

by ashoeafoot

5/15/2026 at 4:52:42 AM

To play doom on it?

by fc417fc802

5/14/2026 at 11:32:37 PM

Implement your own payment provider

by NewJazz