UPDATE: Apple issued a fix for this bug on Feb. 19 via iOS 11.2.6.

A symbol in the Indian language known as Telugu can wreak havoc on iOS.

Apple iOS 11 will struggle to render it whenever the symbol is placed into a text field. Apps that try to do so will freeze and shut down.

The problem gets worse when chat or email apps get involved. PCMag tried the bug on an iPad by sending it messages loaded with the Telugu symbol. Mayhem ensued. The iPad immediately crashed when the messages were received; iOS's notification bar failed to process them, forcing the whole system to stop and reload.

The problems don't end there. Messages written with the Telugu symbol can effectively disable any chat or email app that tries to fetch them on startup. Facebook Messenger, for instance, shut down whenever it came across a chat containing the symbol.

Making matters worse is how other apps, like Yahoo Mail, can constantly trigger the bug when iOS goes idle. That's because the apps will persistently try to display emails carrying the Telugu symbol as a notification. As a result, our iPad was stuck in a cycle of periodic iOS freezes.

Engineers at software maker Aloha Browser warned about the bug earlier this week. The symbol is actually several Telugu characters, and the error is caused when the default San Francisco font across Apple devices tries to render them, Aloha browser said in a tweet.

Google Translate says the characters mean the word "sign." However, a PCMag reader who speaks Telugu said the symbol is actually a syllable with no real meaning. "So in that sense it stumps both translate and iOS," the reader said in an email. "If I have to transliterate as it sounds phonetically, it would be gnya."

Unfortunately, iOS isn't the only operating system affected. The bug can also be reproduced on macOS High Sierra (version 10.13), along with the new versions of tvOS and watchOS.

The good news is that the Telugu symbol doesn't appear to trigger an error when viewed over an internet browser, unless you try pasting it into a text field like the web address bar. Apple says it's also working on a fix that should be arriving soon. Beta versions of iOS, macOS, watchOS and tvOS are free of the flaw.

The problem joins a number of iOS bugs involving rigged messages that can disrupt the system. Last month, a software developer found he could overload an iPhone owner's Messages app by sending it a specially crafted web link. Phones that received the link would freeze and possibly restart. Fortunately, Apple quickly issued a fix.

The Telugu bug is certainly problematic. Imagine an internet troll bombarding you with messages containing the symbol. But fixing a device saddled with the bug can be done. When it came to our iPad, we had to delete the Telugu character-containing emails from our Yahoo Mail account using a web browser. Then we re-installed the Yahoo Mail app over the iPad.

UPDATE 2/16:

A Mozilla research engineer has said that more than one symbol can trigger the bug. Apparently, the error can be reproduced in Telugu, Devanagari and Bengali scripts when certain characters are arranged in a special sequence.

The engineer, Manish Goregaokar, has written a blog post on the subject. So far, Apple hasn't commented.

For now, both Facebook and Twitter have been blocking users from posting the original Telugu symbol, calling it spam. However, some Twitter users have managed to slip it into their screen names. These users can potentially disable your Twitter app if they like, retweet or reply to one of your tweets.

One security researcher has also showed what happens when a Wi-Fi network is renamed with the symbol. Trying to pull up the Wi-Fi hotspot over your Mac will trigger the machine's network app to crash.

Editor's Note: This story was updated with info about the symbol's meaning.

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