macOS Monterey 12.2 and iOS 15.3 Release Candidates Fix Safari Bug That Leaks Browsing Activity

The macOS Monterey 12.2 and iOS 15.3 release candidates that came out today appear to address a Safari bug that could cause your recent browsing history and details about your identity to be leaked to malicious entities.

safari icon blue banner
As shared last week by browser fingerprinting service FingerprintJS, there is an issue with the WebKit implementation of the IndexedDB JavaScript API. Any website that uses IndexedDB can access the names of IndexedDB databases generated by other websites during the same browsing session.

The bug permits a website to spy on other websites that the user visits while Safari is open, and because some websites use user-specific identifiers in their IndexedDB database names, personal information can be gleaned about the user and their browsing habits.

Browsers that use Apple's WebKit engine are impacted, and that includes Safari 15 for Mac and Safari for iOS 15 and iPadOS 15. Some third-party browsers like Chrome are also affected on iOS and iPadOS 15, but the macOS Monterey 12.2, iOS 15.3, and iPadOS 15.3 updates fix the vulnerability.

FingerprintJS constructed a demo website to let users check to see whether they're impacted, and as 9to5Mac notes, after updating to the new software, the website detects no security holes.

The website is designed to tell users details about their Google accounts. On iOS 15.2.1 and macOS Monterey 12.1, we tested and the demo website was able to detect our Google account. After updating to the macOS Monterey 12.2 RC and the iOS 15.3 RC, the demo website no longer detects any data.

Apple earlier this week prepared a fix for the bug and uploaded it to the WebKit page on GitHub, so we knew that Apple was working to address the vulnerability. With the macOS Monterey 12.2 and iOS 15.3 release candidates now available, we could see these updates be made available to the public as soon as next week.

Tag: Safari
Related Forums: iOS 15, macOS Monterey

Popular Stories

iOS 26

Everything New in iOS 26.2 Beta 3

Monday November 17, 2025 3:20 pm PST by
Apple provided developers with the third beta of an upcoming iOS 26.2 update, and there are still new features that are being added with each beta that we get. We've rounded up all of the changes that Apple made in beta 3. AirDrop Apple added new AirDrop functionality, providing a way for two people to share files temporarily without having to add one another as contacts. iOS 26.2...
applecare apple care banner

Apple Brings New AppleCare+ Options to India

Tuesday November 18, 2025 8:42 am PST by
Apple today announced an expansion of AppleCare+ coverage in India, with new options for monthly and annual plans, and the addition of Theft and Loss for iPhone for the first time. Options for monthly and annual AppleCare+ plans in India provide more choice and flexibility, allowing users to keep coverage for as long as they require. Apple's vice president of Worldwide iPhone Product...
Apple Wallet ID Illinois

iPhone Driver's License Feature Launching in Illinois

Tuesday November 18, 2025 8:47 am PST by
In select U.S. states, residents can add their driver's license or state ID to the Wallet app on the iPhone and Apple Watch, providing a convenient and contactless way to display proof of identity or age at select airports and businesses, and in select apps. Starting this Wednesday, November 19, the feature will be available to residents of Illinois. The announcement confirmed that the...
iPhone 17 Pro Cosmic Orange

10 Reasons to Wait for Next Year's iPhone 18 Pro

Wednesday November 19, 2025 4:00 am PST by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models at the same time, which is why we often get rumored features months ahead of launch. The iPhone 18 series is no different, and we already have a good idea of what to expect for the iPhone 18 Pro and iPhone 18 Pro Max. One thing worth...
iPhone 17 Pro and Air N1 Feature

iPhone 17 vs. iPhone 16 Wi-Fi Speeds: New Study Reveals the Winner

Tuesday November 18, 2025 10:53 am PST by
A new study has revealed that the iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, and iPhone Air achieve significantly faster average Wi-Fi speeds compared to the iPhone 16 series, thanks to Apple's custom-designed N1 chip. The study was conducted by Ookla, the company behind the popular Speedtest website and app. It said the results are based on global, crowdsourced Speedtest user data...
Magic Keyboard Touch ID Feature

Apple Releases New Firmware for 140W USB-C Power Adapter, Magic Keyboard and Magic Trackpad

Tuesday November 18, 2025 1:05 pm PST by
Apple today released updated firmware for several accessories, including the 140W USB-C Power Adapter, the Magic Trackpad 2, the Magic Trackpad USB-C, the Magic Keyboard with Touch ID, and the Magic Keyboard with Touch ID and Numeric Keypad. There is no word on what's included in the updated firmware at this time, but it could offer performance improvements and security updates. Accessory...
macbook black friday

The Best Early Black Friday Mac Deals

Tuesday November 18, 2025 7:32 am PST by
We're getting closer to Black Friday, which lands next week on Friday, November 28. In the lead-up to the shopping holiday, we're tracking a few lowest-ever prices on Apple's most popular Macs, including the M4 MacBook Air and brand new M5 MacBook Pro. Note: MacRumors is an affiliate partner with some of these vendors. When you click a link and make a purchase, we may receive a small payment,...
Apple Sports App Preview Feature

Apple Sports App on iPhone Now Available in More European Countries

Monday November 17, 2025 6:27 am PST by
The free Apple Sports app on the iPhone was released in additional European countries today, including Belgium, Croatia, Czechia, the Netherlands, Luxembourg, Poland, Hungary, Denmark, Finland, Norway, Sweden, Switzerland, Slovakia, Slovenia, Serbia, Greece, Estonia, Latvia, Romania, Ukraine, and others. The app was already available in the U.S., the U.K., Canada, Austria, France, Germany,...
best early black friday deals

Best Black Friday Apple Deals Live Now - Save on AirPods, iPads, and Apple Watches

Saturday November 15, 2025 1:45 pm PST by
We're officially in the month of Black Friday, which will take place on Friday, November 28 in 2025. As always, this will be the best time of the year to shop for great deals, including popular Apple products like AirPods, iPad, Apple Watch, and more. In this article, the majority of the discounts will be found on Amazon. Note: MacRumors is an affiliate partner with some of these vendors. When ...
AirPods Pro Firmware Feature

Apple Releases New Firmware for AirPods Pro 2, AirPods Pro 3, and AirPods 4

Thursday November 13, 2025 11:35 am PST by
Apple today released new firmware designed for the AirPods Pro 3, the AirPods 4, and the prior-generation AirPods Pro 2. The AirPods Pro 3 firmware is 8B25, while the AirPods Pro 2 and AirPods 4 firmware is 8B21, all up from the prior 8A358 firmware released in October. There's no word on what's include in the updated firmware, but the AirPods Pro 2, AirPods 4 with ANC, and AirPods Pro 3...

Top Rated Comments

Dave-Z Avatar
50 months ago

As discovered last week ('https://www.macrumors.com/2022/01/16/safari-15-webkit-indexeddb-bug/') by browser fingerprinting service FingerprintJS
It wasn't discovered last week. It was discovered last year, November 2021. It was disclosed to the public last week.


we knew that Apple was working to address the vulnerability in a timely manner
Addressing the issue nearly two months after it having been reported is not timely, especially considering this patch still hasn't reach the public. If the update comes out in one week that will have been two months since Apple first learned about it.
Score: 31 Votes (Like | Disagree)
centauratlas Avatar
50 months ago
"address the vulnerability in a timely manner.".

But is it really timely? Sure, timely since it was made public, but was it timely since they first were informed of it? I'd say no.
Score: 16 Votes (Like | Disagree)
CaTOAGU Avatar
50 months ago
It really does feel a bit silly that we’re still having to wait on OS level updates to fix a bug in a web browser.
Score: 15 Votes (Like | Disagree)
IGI2 Avatar
50 months ago

It wasn't discovered last week. It was discovered last year, November 2021. It was disclosed to the public last week.



Addressing the issue nearly two months after it having been reported is not timely, especially considering this patch still hasn't reach the public. If the update comes out in one week that will have been two months since Apple first learned about it.
But to be fair, Google Project Zero (and others) has a disclosure policy of 90 days.

We know that this is a privacy breach, but still, modern OSs are fairly complex. Getting to know about it, analysis, fixing it, incorporating in all variants, QA testing, and distributing it to all end users across the globe in one time, whether it's iPhone 6s or iPhone 13 Pro Max is still within reasonable "timely" manner.

We know that they had some public pressure; that's why it's even shorter if we count days since it landed in the news.
Score: 9 Votes (Like | Disagree)
beanbaguk Avatar
50 months ago
To all those members complaining about the "timely manner" statement. I would say this is very timely and your complaints indicate you have no experience in software development.

I've been in software development for many years (I am a Head of Product at a software technology company), and patching something isn't just a 5-minute job, even if you know what the issue is and how to fix it.

A small change on an API will impact many, many areas of a product and this means thorough testing is required, and diligence of any related libraries and products.

This is hugely time-consuming and since this product impacts so many platforms, it's not just a case of patching and letting it go into the wild. Especially in this instance, a security audit would have to also be conducted to show the result works, and this would have to be verified by multiple organisations.

Then, the patch has to be tested to ensure it deploys safely and correctly over the air. That update process takes time to implement, manage and check. It then needs checking again, more testing and feedback from users (beta), and devs to ensure they are not experiencing any issues. Again, all this takes time.

I hope this provides some perspective as to how and why these fixes take a little time.

It reminds me of the days when I used to build websites for clients. Talking to an individual who has zero ideas as to the complexities of a solid product is the most infuriating and patience-testing experience as a developer.

Anyway. Two months for a fix like this on this scale is perfectly acceptable.
Score: 8 Votes (Like | Disagree)
Macintosh TV Avatar
50 months ago
Mozilla has security issues that are more than 2 years old and filed in their system. Chrome has outstanding security issues older than this. Folks need to settle down. This stuff happens. It gets fixed. If you're unhappy with the speed at which a browser or OS patches issues, then it may be time to look elsewhere.
Score: 8 Votes (Like | Disagree)