Apple Stops Signing iOS 18.6, Downgrading No Longer an Option - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

Apple Stops Signing iOS 18.6, Downgrading No Longer an Option

by

Apple is no longer signing iOS 18.6, making downgrades from iOS 18.6.2 or iOS 18.6.1 to iOS 18.6 impossible. iOS 18.6.1 was released a little over a week ago, swiftly followed by iOS 18.6.2 on Wednesday.

iOS 18
Apple often stops signing an older version of iOS, usually within a week or two after a new version is released. When an update is no longer signed, it can't be installed on an ‌iPhone‌ due to a server-side software verification check.

By no longer signing a software version, Apple ensures that customers have the latest security improvements and are not vulnerable to known attacks.

Apple's iOS 18.6.1 update re-enables blood oxygen monitoring in the United States for the Apple Watch Series 9, Apple Watch Series 10, and Apple Watch Ultra 2 running watchOS 11.6.1, which was released concurrently. That was quickly followed by iOS 18.6.2, providing important security fixes.

Popular Stories

macOS 27 on MacBook Pro

Apple Says macOS 27 Won't Be Compatible With These Macs

Wednesday June 3, 2026 8:29 am PDT by
During WWDC 2025, Apple revealed that macOS 26 Tahoe would be the final major macOS version for Intel-based Macs. macOS 27 will be compatible with Apple silicon Macs only, meaning that you will need a Mac with an M-series chip or a MacBook Neo with an A18 Pro chip in order to install the software update. Apple will unveil macOS 27 during its WWDC 2026 keynote this Monday, June 8, and the...
Read Full Article • 90 comments
MacBook Neo on Yellow Feature

MacBook Neo is So Popular That Apple Reportedly Doubled Production

Wednesday June 3, 2026 9:24 am PDT by
On an earnings call in late April, Apple's CEO Tim Cook said that customer response to the MacBook Neo was "off the charts," and the popularity of the laptop has reportedly led the company to significantly boost production. Apple supply chain analyst Ming-Chi Kuo this week said he believes that MacBook Neo shipments to Apple were doubled from an initial target of 5 million units to 10...
Read Full Article • 115 comments
iphone 18 pro blue%402x

iPhone 18 Pro: Dark Cherry, Light Blue, and Dark Gray Chassis Leaked [Update]

Thursday June 4, 2026 5:18 am PDT by
Update: Since publication, new information has come to light suggesting the images have been AI-manipulated and are not in fact iPhone 18 Pro chassis parts. The original article follows. The color options Apple is reportedly planning for the upcoming iPhone 18 Pro and ‌iPhone 18 Pro‌ Max have appeared online today in the form of images of chassis parts of unknown authenticity....
Read Full Article • 74 comments

Top Rated Comments

winxmac Avatar
winxmac
10 months ago
iOS 18.6 - 29th July 2025
iOS 18.6.1 - 14th August 2025
iOS 18.6.2 - 20th August 2025

Just about 3 weeks to go before iOS 18.7 which is my next update. I'm happy with iOS 18.6 although not entirely because of the redesigned Photos app.
Score: 2 Votes (Like | Disagree)
xaanaax Avatar
xaanaax
10 months ago
Does anyone care?
Score: 1 Votes (Like | Disagree)
C
Carefless
10 months ago
Can we stop with this "news"? Leave it to junk websites like 925. Nobody cares about downgrading, it's not something people do regularly.
Score: 1 Votes (Like | Disagree)
ClaraStahlbaum Avatar
ClaraStahlbaum
10 months ago
Unpopular opinion but I personally support the fact they are doing this.
Score: 1 Votes (Like | Disagree)
glsillygili Avatar
glsillygili
10 months ago

Okay, I seemed quite sure to stay in iOS 18.6.1, because the performance and battery life were very good, right?

However, it’s wise to have second thoughts, and I’ve been doing my research on the vulnerability patched in 18.6.2: CVE-2025-43300. It seems serious and juicy enough to consider patching it if the battery loss is not too big.

From what I’ve read, now that the patch is out there, comparing it to the previous update bad actors (at least those that still didn’t know the issue) could reverse engineer the patch to discover the vulnerability and build stronger attacks into all sorts of image files that then will be parsed by ImageIO.

Also, the fact that it’s being patched in iOS 17.7.10 indicates that the vulnerability probably wasn’t introduced with iOS 18 or a later update, but rather it has been there dormant since who knows when. IIRC the image parser ImageIO dates the Tiger days, so…

Don’t get me wrong. I’m really pissed off because it is known that this newest version is giving some sporadic problems and the battery life is lower. Let’s cross our fingers for it to not make the devices overheat. But I think the vulnerability is, this time, important enough for Apple to issue a second update to 18.6, to release it quite urgently (a patch for only one vulnerability), that it might be worth the trade off of a worse battery life.

Damn, I wish Apple’s security patches didn’t affect performance and efficiency of the devices…
I don't think there is any battery life change in a minor update?
Score: 1 Votes (Like | Disagree)
Populus Avatar
Populus
10 months ago
Okay, I seemed quite sure to stay in iOS 18.6.1, because the performance and battery life were very good, right?

However, it’s wise to have second thoughts, and I’ve been doing my research on the vulnerability patched in 18.6.2: CVE-2025-43300. It seems serious and juicy enough to consider patching it if the battery loss is not too big.

From what I’ve read, now that the patch is out there, comparing it to the previous update bad actors (at least those that still didn’t know the issue) could reverse engineer the patch to discover the vulnerability and build stronger attacks into all sorts of image files that then will be parsed by ImageIO.

Also, the fact that it’s being patched in iOS 17.7.10 indicates that the vulnerability probably wasn’t introduced with iOS 18 or a later update, but rather it has been there dormant since who knows when. IIRC the image parser ImageIO dates the Tiger days, so…

Don’t get me wrong. I’m really pissed off because it is known that this newest version is giving some sporadic problems and the battery life is lower. Let’s cross our fingers for it to not make the devices overheat. But I think the vulnerability is, this time, important enough for Apple to issue a second update to 18.6, to release it quite urgently (a patch for only one vulnerability), that it might be worth the trade off of a worse battery life.

Damn, I wish Apple’s security patches didn’t affect performance and efficiency of the devices…
Score: 1 Votes (Like | Disagree)
Read All Comments