Update Your iPhone to Prevent People From Seeing iMessages They Shouldn’t

Has this ever happened to you? You add someone new to an iMessage group chat, and wonder, “Huh, can they see any of the messages from before they were added?” The answer to that question is supposed to be “no.” By design, new iMessage group chat members are only privy to texts that arrive after they were added. When they join, it’s essentially a blank slate, as if you just created the group for the first time. At least, that’s how it’s intended to work.

iMessage currently has two security flaws

As it turns out, there’s a bug with iMessage that may allow new group chat members to see texts from before they were added to the chat. That’s a problem, and not just for the iPhone users out there talking smack about people before inviting them to join the group chat. It means iMessage, and Apple’s platforms in general, aren’t working like they’re supposed to be. You don’t have to be talking behind people’s backs to not want new members seeing existing chats. Maybe you’re planning a surprise party for someone, and add them to the group once everyone’s in on the plan; maybe the texts in the chat aren’t relevant to the current group, and the person joining simply does not need to access them.

That’s not all: There exists another security flaw that could allow remote hackers to join an iMessage group and receive new messages. You might add a new user to a group chat and inadvertently invite them to read all existing messages, while at the same time being attacked by a bad actor who can then intercept all future messages. Not good.

iOS 27.2.1 patches this bug and eight more

Luckily, there’s currently a fix for these problems. Apple patched (and revealed) the bugs, along with seven other security flaws, with a series of software updates on Monday for iPhone, iPad, Mac, Apple Watch, and Vision Pro. Not all of the updates include patches for these two iMessage flaws—specifically, some of the updates for older Apple devices. But the rest, including iOS 27.2.1, macOS 27.2.1, macOS 26.7.3, macOS 15.8.3, watchOS 27.2.1, and visionOS 27.2.1, include the iMessage patches.

Each update includes its own list of patches, but, for this article, I’ll take a look at the nine patches in iOS 27.2.1. You’ll find the two iMessage bugs, plus seven other patches, in the list below: