Friday, September 18 is iPhone 18 Pro launch day. Software Update still shows two public tracks for older phones. One is iOS 27.0 build 24A437. The other is iOS 26.7 build 23H24 for people who stay on the previous major version. Apple listed both on its security releases page on September 14.
That split is separate from the factory builds on new Pro boxes. Those units need a day-one bump to 24A437, as covered in today’s iPhone 18 Pro day-one update notes. This piece sticks to the confirmed public and companion strings you can check in Settings after install.
Confirmed public builds on September 18
Apple’s developer releases feed and the security index agree on the shipping numbers below. After an update finishes, open Settings, General, About. The build sits in parentheses on the Software Version line.
| Platform | Version | Build | Notes |
|---|---|---|---|
| iOS | 27.0 | 24A437 | Public launch build, Sept 14 |
| iPadOS | 27.0 | 24A437 | Same build as iOS 27.0 |
| iOS / iPadOS | 26.7 | 23H24 | Security track if you skip 27 |
| watchOS | 27.0 | 24R364 | Public watch launch build |
| tvOS | 27.0 | 24J361 | Listed on developer releases |
| visionOS | 27.0 | 24M362 | Listed on developer releases |
| macOS | 27.0 | 26A428 | Golden Gate public build |
iPadOS 26.7 also uses 23H24 on the developer feed. The prior iOS 26.6.2 point build was 23G90 on September 8. That one had no published CVE entries. 26.7 is the security package Apple wants on devices that remain on the 26 line.
How Software Update presents the choice
On phones still running iOS 26, MacRumors reported that 26.7 appears as the default update. iOS 27 sits lower on the same screen as an optional upgrade. Apple has not published a date for when 27 becomes the only highlighted row. Until then, the stay-on-26 path is intentional, not a leftover beta.
Apple’s security page for iOS 27 and iPadOS 27 went live September 14. A separate page covers iOS 26.7 and iPadOS 26.7 from the same day. Independent tallies put more than 100 fixes on the 27 page and a large shared set on 26.7. Apple has not marked any of those CVEs as actively exploited. Readers who already followed the iOS 27 shipping build 24A437 note can treat 23H24 as the matching number for the older branch.
What Apple has not confirmed
There is still no public iOS 27.1 row on the developer releases feed. Apple seeded iOS 27.2 beta instead. That seed is build 24B5084k for iOS and iPadOS, logged in yesterday’s 27.2 developer beta build list. Companion 27.2 betas for macOS, tvOS, visionOS, and watchOS are on the same September 16 list.
Apple has not published a security content page for any 27.2 beta. Build strings on a developer seed are not the same as a shipping advisory. Apple also has not confirmed a public release date for 27.1 or 27.2 in the releases feed itself. Outside reports tie 27.1 to iPhone Duo later in October. That schedule is not on Apple’s releases page.
Quick checks for launch Friday
If you keep an older iPhone on iOS 26 for now, install 26.7 and verify 23H24 under About. If you already moved to iOS 27, you want 24A437, not a factory Pro string and not the 27.2 beta unless you opted into the developer track. New Apple Watch Series 12 and Ultra 4 pairings may still ask for watchOS 27 build 24R364 after a factory 24R359 install. That watch detail sits next to the Pro phone checklist in the day-one news piece linked above.
Developers who jumped to 24B5084k should expect more beta churn before any public 27.2. Everyone else can stay on the September 14 public builds until Apple posts a new security row or a new public version string on the releases feed.
Photo: Apple
Source: Apple Developer / Apple Support / MacRumors
