iOS 26.0.1 And iOS 18.7.1—Update Warning Issued To All iPhone Users

Apple iOS 26.0.1 displayed on an iPhone 16 Pro screen

Update Oct. 02, 2025: This article, originally published on Sept.30, has been updated to include details of bugs fixed in iOS 26.0.1, adds news of iOS 26.1 and asks whether you should upgrade your iPhone to the latest version.

Apple has issued iOS 26.0.1 and iOS 18.7.1, along with a warning to update your iPhone now. That’s because both iOS 26.0.1 and iOS 18.7.1 address a single security vulnerability in the iPhone maker’s operating system.

Apple doesn’t give much detail about what’s fixed in iOS 26.0.1 and iOS 18.7.1, to allow as many iPhone users as possible to update before attackers can get hold of the information.

However, iOS 26.0.1 and iOS 18.7.1 both fix the same security flaw in FontParser — a part of Apple’s operating system that processes font files — which could see unexpected app termination or corrupted process memory, if an iPhone user processes a maliciously crafted font. Tracked as CVE-2025-43400, the out-of-bounds write issue was addressed with improved bounds checking, according to Apple’s support page.

“The flaw could be triggered by a malicious font delivered via a document, email attachment, or web content, and may lead to unexpected application termination or memory corruption,” says Adam Boynton, senior security strategy manager EMEIA at cybersecurity outfit Jamf.

On its own, the vulnerability fixed in iOS 26.0.1 and iOS 18.7.1 does appear to “have a relatively low risk,” says Sean Wright, head of application security at Featurespace.

However, he warns that memory corruption “could potentially lead to more severe exploits such as code execution or privilege escalation.”

iOS 26.0.1 Fixes Bugs In the iOS 26 Update

When a new iPhone software is released, it will inevitably include bugs. However, those who already updated to iOS 26 will find many of the issues are fixed in the latest iOS 26.0.1 update. The iOS 26.0.1 upgrade apparently squashes bugs including issues with the iPhone’s Wi-Fi impacting iPhone 17 models.

Meanwhile, a small number of iPhone users may be unable to connect to a cellular network after updating to iOS 26, Apple said, adding that this should now be fixed.

Another bug addressed is a problem with photos taken under certain lighting conditions with iPhone 17, iPhone Air and iPhone 17 Pro models, which could include “unexpected artifacts,” Apple said.

Another bug fixed saw app icons appearing blank after adding a custom tint.

The iOS 26.0.1 update squashes a bug that could see VoiceOver become disabled for some users after updating to iOS 26.

Apple says that the macOS 26.0.1 update includes non-specific bug fixes and also addresses a problem that was keeping some users of this year’s high-end M3 Ultra Mac Studio from installing the update, according to tech site Ars Technica. The tvOS update fixes a problem that could cause audio to desync from video in some apps.

Many iPhone users who have already updated to iOS 26 expressed relief about the release of iOS 26.0.1. On a thread on Reddit, one user said: “I can say for sure that overall performance is a ton better and my keyboard lag is gone! So far not stuttering either.”

Others questioned whether all the bugs were fixed in iOS 26.0.1. “By the amount of bugs in iOS 26, I doubt they can even fit every bug fix into one update,” one person posted on Reddit. “I’d guess it takes at least two more to make it run somewhat decent.”

Apple is releasing iOS 26.1 soon, so hopefully there will be more bug fixes coming.

iOS 26.0.1 V iOS 18.7.1 — Which New iPhone Upgrade Should You Choose?

Both iOS 26.0.1 V iOS 18.7.1 fix a single security issue, so one of them must be applied now. But which of the two iPhone upgrades should you choose?

Many people have delayed updating to iOS 26, to avoid early bugs in the initial release. It’s a fair decision to make, especially if you can’t stand bugs or if you use your iPhone for work and it would therefore impact your productivity.

So, has enough changed after the release of iOS 26.0.1 to make updating to the latest version worth it? If you are on iOS 18.7 and stayed there for one of the above reasons, maybe not. While it’s clear iOS 26.0.1 has addressed a number of bugs in the new iOS operating system, it’s still very early in its release.

However, if you have simply not updated at all and are considering trying iOS 26, iOS 26.0.1 is a good bet to endure less bugs than you would have a month ago. The update also includes a bunch of very cool new features for your iPhone, including many driven by Apple Intelligence AI. One of my favorite new features is the ability to screen calls from unknown numbers in iOS 26, because I do receive quite a few of those in my job.

Apple will ask if you want to enable this iOS 26 feature and if you do so, it will require anyone calling from a number outside your phone book to announce themselves, or the call won’t go through. Handy for sales calls or other unwanted contact.

If you are very adverse to bugs, it might not be time to update to iOS 26.0.1. You could wait for iOS 26.1 in around a month, but you must update to iOS 18.7.1 to keep your iPhone safe.

Other Updates Issued Alongside iOS 26.0.1 And iOS 18.7.1

Alongside iOS 26.0.1 and iOS 18.7.1, Apple has issued updates for iPads, Macs, Apple TVs, Apple Watches and its Apple Vision Pro. All of these fix the single Font Parser bug and the patch must be applied as soon as possible.

iOS 26.1 Comes With More Cool iPhone Features

Apple’s iOS 26.1 is on its way, probably towards the end of this month or early next, with some very cool new features. One of these will be a huge boost for iPhone security. Yes, you guessed it, it’s the return of the Rapid Security Responses — iPhone updates performed on the fly, in the background and separately from bug fixes and features.

Apple first introduced Rapid Security Responses in iOS 16, but soon, one of these went wrong and Apple was forced to quickly issue another update to fix it. After that, no further Rapid Security Responses were ever seen.

With iOS 26.1, Rapid Security Responses are back, under the new name Background Security Improvements. I, for one, can’t wait.

So, when exactly could iOS 26.1 arrive? Apple-focused site 9to5Mac predicts the next iPhone update will arrive in Oct. Its prediction is based on release dates for the last few years of x.1 updates. For example: iOS 18.1 was released on Monday, Oct. 28; iOS 17.1 was issued on Wednesday, Oct. 25.

“Based on Apple’s history, iOS 26.1 is expected to launch in late October, likely around October 27,” 9to5Mac writes. “Monday, October 27 seems the best candidate for release day, but it could always be a little earlier or later. Any time during the week of October 20 is certainly possible, but around the 27th would be my best guess based on historic patterns.”

I would guess Oct.28, since Apple recently likes to issue iOS updates on a Monday.

Why You Should Update To iOS 26.0.1 Or iOS 18.7.1 Now

The single issue patched in iOS 26.0.1 and iOS 18.7.1 has not been used in real-life attacks yet. But it’s still a good idea to update now — especially if you want to fix any bugs in iOS 26.

Wright thinks the fact that iOS 18.7.1 and iOS 26.0.1 came with a single security fix probably means that the patch is important. “It does warrant the question as to why this update has been released for this specific vulnerability only,” he says.

Boynton says the issue “has the potential to cause service disruptions or undermine system stability.”

With this in mind, he “strongly recommends updating to iOS 26.0.1 at your earliest convenience.”

But at the moment, you can still choose which iPhone upgrade to apply.

iOS 26.0.1 is available for iPhone 11 and later, iPad Pro 12.9-inch 3rd generation and later, iPad Pro 11-inch 1st generation and later, iPad Air 3rd generation and later, iPad 8th generation and later, and iPad mini 5th generation and later.

Meanwhile, iOS 18.7.1 is available for iPhone XS and later, iPad Pro 13-inch, iPad Pro 12.9-inch 3rd generation and later, iPad Pro 11-inch 1st generation and later, iPad Air 3rd generation and later, iPad 7th generation and later, and iPad mini 5th generation and later.

So, what are you waiting for? Go to your Settings > General > Software Update and download and install iOS 26.0.1 or iOS 18.7.1 now.

Forbes