Mozilla accidentally leaks 76,000 developers' email addresses, 4,000 passwords

Firefox
Leaky times for the Firefox maker

Firefox maker Mozilla has fallen foul to a security breach that exposed personal data relating to members of its Mozilla Developer Network (MDN).

In a co-authored blog post, Stormy Peters, head of Mozilla's developers unit, and Joe Stevenson, its head security honcho, wrote that a failed data sanitization process of the MDN's site database caused email addresses belonging to 76,000 users and encrypted passwords of around 4,000 users to be dumped onto a publicly viewable server.

The snafu went unnoticed for 30 days until being picked up by a web developer on July 23, according to Mozilla, which immediately removed the data dump from the server and disabled the offending process.

Safe move

The company wrote that it hasn't detected any malicious activity on the server in question but encouraged users to change their login details to be on the safe side.

"The encrypted passwords were salted hashes and they by themselves cannot be used to authenticate with the MDN website today," Peters and Stevenson wrote. "Still, it is possible that some MDN users could have reused their original MDN passwords on other non-Mozilla websites or authentication systems.

"We've sent notices to the users who were affected. For those that had both email and encrypted passwords disclosed, we recommended that they change any similar passwords they may be using."

Kane Fulton
Kane has been fascinated by the endless possibilities of computers since first getting his hands on an Amiga 500+ back in 1991. These days he mostly lives in realm of VR, where he's working his way into the world Paddleball rankings in Rec Room.
Latest in Security
Data leak
Top home hardware firm data leak could see millions of customers affected
Representational image depecting cybersecurity protection
Third-party security issues could be the biggest threat facing your business
A stylized depiction of a padlocked WiFi symbol sitting in the centre of an interlocking vault.
Broadcom warns of worrying security flaws affecting VMware tools
Android Logo
Devious new Android malware uses a Microsoft tool to avoid being spotted
URL phishing
HaveIBeenPwned owner suffers phishing attack that stole his Mailchimp mailing list
Ransomware
Cl0p resurgence drives ransomware attacks to new highs in 2025
Latest in News
Buzz Lightyear Space Ranger Spin Rennovations
Disney’s giving a classic Buzz Lightyear ride a tech overhaul – here's everything you need to know
Hisense U8 series TV on wall in living room
Hisense announces 2025 mini-LED TV lineup, with screen sizes up to 100 inches – and a surprising smart TV switch
Nintendo Music teaser art
Nintendo Music expands its library with songs from Kirby and the Forgotten Land and Tetris
Opera AI Tabs
Opera's new AI feature brings order to your browser tab chaos
An image of Pro-Ject's Flatten it closed and opened
Pro-Ject’s new vinyl flattener will fix any warped LPs you inadvertently buy on Record Store Day
The iPhone 16 Pro on a grey background
iPhone 17 Pro tipped to get 8K video recording – but I want these 3 video features instead