Link: https://arstechnica.com/security/2026/10/the-internet-goes-on-high-alert-after-discovery-of-8-compromised-tls-certs/

Astonishingly, the private keys were 4, 56, 66, 115, 155, 156, 230, 237.

exploiting compromised certificates requires an active adversary-in-the-middle attack, meaning the attacker must act as a proxy between two TLS parties and receive encrypted traffic, decrypt it, reencrypt it, and send it to the other party. Such capabilities, in some cases, are usually limited to only the most well-resourced attackers. People with control of a local network—at a coffee shop, university, or other organization—face much less of a challenge.

https://emudhra.we-have-a-problem.com/

Okay, that's fun and scary at the same time.

The article links to a webpage,

https://emudhra.we-have-a-problem.com/

That shows if your browser is still using those certs, and though it says Firefox has already updated, maybe it hasn't reached mobile yet as it shows I'm using them all still.

I guess I won't connect to anything important for a few days.

arrgh. got to get off my lazy ass and do a thorough updating this weekend.

My Firefox mobile got green ✅

Maybe try manually updating through the app store

I'm using Firefox and that site says I'm good.

So if my understanding is correct, to be exploited the attacker would already need to be in a position to intercept your traffic, but this means when they do they can effectively impersonate anyone.

This could actually be an interesting attack vector for hacking IOT devices. If you control the DNS server the device connects to you can get it to trust literally anything.

I'm on a 10/7 build and I'm vulnerable on mobile FireFox, as well.

Edit: updated to a 10/19 version, 158.0.1, and it's still vulnerable.

In app safari on Mlem got all greens.

Ironfox is all green for me.

Cromite is half red, half green.

So yeah, fuck Chromium's monopoly.

MITM HTTPS traffic without a key doesn't really let you do much of anything, especially with stuff like HSTS. You can mess with DNS, but the whole certificate authority thing is meant to make it so you can't redirect someone's traffic to a malicious server.

This leaked private key completely destroys that guarantee, making it extremely scary. ~Plus, saved traffic for any site signed by this key which didn't use PFS will be subject to post-facto decryption.~

edit: I don't know wtf I was thinking, the decryption thing is nonsense.

Yep, my Firefox mobile hasn't updated yet either, gonna see if there's an update I can grab.

For mobile

• Vanadium 155.0.8059.84 (config 217) on GrapheneOS connects to 6/12 0/12. Last updated 2026-10-17
• Fennec 158.0.0 (build #1580020) connects to 12/12. Last updated 2026-10-14
• edited: after I hit 'run again' a couple times Vanadium went 0/12, so hurray. Didn't make a difference to my dear Fennec though.

I don't think so about the post-facto decrypt. Keyexchange runs with the certs of the destination server. The cerst affected by the leak are intermediate certs which give trust to a cert chain AFAIK.

You're absolutely right, I had shit all mixed up in my head. Oops 😅 thank you for the correction.

What's odd is that I have auto updates disabled for Firefox on my spare phone, and I still show green on everything. I don't think it's updated in a couple months now.

what version are you on?

My Vanadium just refused all 12 connections. But maybe some of the DNS blocking or Suricata on my LAN might have helped.

Waterfox on android is in the clear

Edit: Build info, just in case

1.2.8.1 (Build #2026380629)

GV: 156.0-20260922074625

AS: 156.0

OS: Android 16

Thanks, I tried harder and got the same result as you. Edited my comment above to reflect.

Useful link, thanks.

Mobile Waterfox passes.

Are you using a vpn/tor?

is the post body having issues displaying? asking because this is way past the first time this season i've seen people not see it

Firefox can push certificate revocation updates without having to push a new browser build

https://hacks.mozilla.org/2025/08/crlite-fast-private-and-comprehensive-certificate-revocation-checking-in-firefox/

On grapheneOS, i just manually disabled the root CA's in the trusted root store.

These are all android versions on graphene:

*There are now 14 certs

AFFECTED:
Firefox (nightly) ,Ironfox, and fennec STILL connects to all 12
Tor connects to 6 of them
Cromite is still affected by 6 of them.

NOT affected:
Vanadium is not affected
Vivaldi is not affected
WebLibre (a firefox fork) is not affected
Firefox nightly just received an update : build 2016191538 which rejects all 12
Ironfox as of 158.0.1 (Build #2016191578) is no longer affected.
Tor is fixed as of 15.0.26 (140.17.0esr) (Build #2016191530)
Fennec all clear

Brave Mobile is green ✅

That one is on version 154.0, dated August.

I just recently swapped to Fennec and it's correctly getting 0/12. These updates seem a bit inconsistent.

Yup.

These days, a lot of firmware blobs are also signed with the vendor's key, so you'd still need to get past that hurdle.

Fennec f-droid didn't connect to any on my test.

My IronFox is clear as per https://emudhra.we-have-a-problem.com/

I think cert updates happen automatically on their own without the browser needing to be updated.

At this early stage, the most immediate threat appears to be for those using VPNs, especially in countries with governments likely to maliciously intercept traffic.

So, all governments?

Same here

I think that this isn't really getting the right attention, about what a massive WTF situation this is...

its a 384 bit certificate and this is the private key

00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:
00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:
00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:
00:00:04

that is just fucking NUTS

Uhh... Weird. In my phone (Android 15) both Firefox 158.0.1 and Brave 1.97.59 (Chromium 155.0.8059.85) connect to 6 of the 12 hosts.

But on my tablet (Android 10) I have the same versions of Firefox and Brave, and there they don't connect to any of the hosts.

What can I do?

Phew to think how close it is to my private key

Odd my mobile Brave rejects all.

First: Who the fuck is eMudhra?

Second: What catastrophic failure of process allows a single point of failure Indian company to compromise the entire internet as we know it by accidentally releasing debug code? Why is it so fragile in the first place?

Fennec and other Firefox forks:
Put

about:config

in address bar and search for

security.enterprise_roots.enabled

Toggle it to True

If your android cert store is good, you will be good for now.
Test it

IronFox all green here

WDYM you're still using them all?

You don't have e any green ticks?

Why would this put vpn users at risk if browsers have already blocked the problematic certs?

It is a problem we all have with dns, namely that the way it works now means we all must trust upstream CAs.

And unfortunately, we will probably suffer a few more of these before we switch over to a voting peer system.

Nice, that's handy

As noted, most browsers have already blocked the intermediate certificates. The exception appears to be Edge running on Windows 10, which at the time this article went live was still connecting to 12 vulnerable hosts.

LOL

I've done this as well, but Fennec doesn't seem to care at all, and still happily connects, even after cache clears and a reboot. Fennec also ignored the about:config change another commenter suggested. Makes no sense. It's pissing me off.

It's displaying fine for me, I think I was just scrolling quickly on my phone and didn't notice that the https://emudhra.we-have-a-problem.com link in the body was different from the linked article. I saw a blockquote in the post body, and figured that the URL beneath the quote was a link to the article.

that’s a very long way to spell the random number 4

eMudhra is an intermediary certificate authority. some of the most popular intermediary CAs* are Sectigo, GlobalSign, MilesWeb, and GeoTrust. would you \^_^/ like to tell me who the heck ✨ these✨ are?

HTTPS has always had a failsafe called certificate revocation. it is working. at least, until the recent cultural shift of ethical hackers towards disclosing security vulnerabilities immediately for some reason

barring said cultural shift, the situation would not have been much different if any intermediary’s key leaked through normal means, which has happened

* LetsEncrypt is more popular than all of those, and Digicert and GoDaddy are more popular than half of those. But that’s where the name recognition ends.

it would put VPN users at risk if browsers had not blocked it or updated enough and the VPN provider chooses to do shenanigans, that’s why security patches patch the security and why it it’s important to patch this security issue