Apple Releases iOS 27 Beta 4: What’s New and How to Install

Apple has released iOS 27 developer beta 4 for compatible iPhones, continuing its testing ahead of the public launch later this year. The update carries build number 24A5390f and replaces beta 3, which arrived earlier this month.



The latest beta is currently available to registered developers. Apple will likely release a matching public beta update after completing additional testing.



How to Update to iOS 27 Beta 4



Before installing the update, back up your iPhone to iCloud or a computer. Beta software can contain bugs that affect battery life, apps, connectivity, and everyday performance.




Open the Settings app on your iPhone.



Go to General.



Tap Software Update.



Select Beta Updates.



Choose iOS 27 Developer Beta.



Return to the previous screen.



Tap Update Now when iOS 27 Beta 4 appears.



Enter your passcode and wait for the installation to finish.




Keep your iPhone connected to Wi-Fi and ensure it has enough battery power before starting the update.



What’s New in iOS 27 Beta 4?



Apple has not announced any major user-facing features for iOS 27 Beta 4 so far. The update appears to focus mainly on fixing bugs, improving stability, and preparing existing iOS 27 features for wider testing.



Early users should look for changes in the following areas:




Performance improvements: Beta 4 should improve general system responsiveness and reduce some of the slowdowns reported in previous builds.



Bug fixes: Apple continues to address crashes, interface problems, broken animations, and other issues found during developer and public testing.



Battery and thermal performance: The update may improve excessive battery drain and device heating, although results can differ between iPhone models.



App compatibility: Developers can use the new build to test their apps against the latest iOS 27 software and API changes.



Siri AI and Apple Intelligence: Apple may continue making server-side and system-level improvements to the new AI features, even when visible changes are limited.




More changes may appear after users spend additional time testing the update. Since this remains an early beta, some features may still fail to work correctly.



If you’ve already installed the update, let us know your experience in the comments.

nmap -sV --script vuln -p- <target-network>

tail -f /var/log/suricata/fast.log | grep <cve>

Check Vendor Security Advisory Bulletin

title: Detect Exploitation - Apple Releases iOS 27 Beta 4: What’s New and How to Install
id: 4984a8a9-0186-495e-b3c9-7356180b8f59
status: experimental
description: Automatisch generierte SIEM-Erkennungsregel basierend auf CTI Intelligence
references:
  - https://tsecurity.de/
author: iShareStuff CTI Automated Detection Engine
date: 2026-09-24
logsource:
  category: network_connection
  product: any
detection:
  selection:
      CommandLine|contains:
        - 'exploit'
  condition: selection
falsepositives:
  - Legitime administrative Zugriffe oder Penetrationstests
level: high
tags:
  - attack.initial_access

rule CTI_Threat_Indicator {
    meta:
        author = "iShareStuff CTI Automated Detection Engine"
        date = "2026-09-24"
        description = "YARA Signature for "
    strings:
        $str = "Apple Releases iOS 27 Beta 4: " ascii wide
    condition:
        any of them
}