CVE-2026-28819 Overview
CVE-2026-28819 is an out-of-bounds write vulnerability [CWE-787] affecting Apple iOS, iPadOS, and macOS. Apple addressed the issue with improved bounds checking across multiple operating system updates. According to Apple's advisory, an app may be able to execute arbitrary code with kernel privileges by exploiting this flaw. The vulnerability is fixed in iOS 18.7.9, iPadOS 18.7.9, macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, and macOS Tahoe 26.5. The issue was assigned an EPSS score of 0.05%, indicating low observed exploitation probability at publication.
Critical Impact
A malicious application installed on an affected Apple device can trigger an out-of-bounds memory write that may lead to arbitrary code execution at the kernel level, undermining the OS security boundary.
Affected Products
- Apple iOS and iPadOS versions prior to 18.7.9
- Apple macOS Sonoma prior to 14.8.7 and macOS Sequoia prior to 15.7.7
- Apple macOS Tahoe prior to 26.5
Discovery Timeline
- 2026-05-11 - CVE-2026-28819 published to the National Vulnerability Database
- 2026-05-13 - Last updated in the NVD database
Technical Details for CVE-2026-28819
Vulnerability Analysis
The vulnerability is an out-of-bounds write [CWE-787] in an Apple operating system component shared across iOS, iPadOS, and macOS. An out-of-bounds write occurs when code writes data past the allocated boundary of a buffer, corrupting adjacent memory. In this case, the write affects kernel memory, allowing an attacker with the ability to run an app on the device to corrupt kernel structures.
Apple's advisories state the issue was resolved by adding improved bounds checking to the affected code path. Apple has not published deeper technical detail beyond confirming arbitrary code execution with kernel privileges is achievable. Successful exploitation breaks the user/kernel privilege boundary that underpins app sandboxing on Apple platforms.
Root Cause
The root cause is missing or insufficient validation of size or index parameters before a memory write operation within a kernel-reachable component. Without proper bounds checks, attacker-controlled input determines the offset or length used in a write, allowing memory adjacent to a target buffer to be overwritten with controlled values.
Attack Vector
Exploitation requires a malicious or compromised application running locally on the device. The application invokes the vulnerable code path with crafted parameters that cause the kernel to perform the out-of-bounds write. From there, attackers typically pivot to corrupting kernel data structures or function pointers to achieve arbitrary code execution at the kernel privilege level. No user interaction beyond running the malicious app is required.
No verified public proof-of-concept code is available for CVE-2026-28819. Refer to the Apple Support Advisory #127111 for additional vendor details.
Detection Methods for CVE-2026-28819
Indicators of Compromise
- Unexpected kernel panics or system reboots correlated with the launch of a specific third-party application.
- Applications requesting or invoking low-level system APIs outside their normal behavioral baseline.
- Newly installed apps from outside the App Store or from unverified developer accounts exhibiting privileged behavior.
Detection Strategies
- Monitor Apple device fleets for systems running iOS/iPadOS versions earlier than 18.7.9 or macOS versions earlier than 14.8.7, 15.7.7, or 26.5.
- Inspect crash reports and ips panic logs on macOS endpoints for repeated kernel faults originating from the same process.
- Correlate process execution telemetry with subsequent privilege-related anomalies such as unsigned kext loads or unexpected entitlement use.
Monitoring Recommendations
- Enforce mobile device management (MDM) compliance policies that flag devices running outdated OS builds.
- Stream endpoint telemetry from macOS hosts into a centralized analytics platform to identify post-exploitation behaviors.
- Track app installation provenance and review apps requesting expanded entitlements following install.
How to Mitigate CVE-2026-28819
Immediate Actions Required
- Update all Apple devices to iOS 18.7.9, iPadOS 18.7.9, macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, or macOS Tahoe 26.5 as applicable.
- Audit installed applications and remove any from untrusted sources or developers.
- Enforce OS version compliance through MDM and block non-compliant devices from accessing sensitive corporate resources.
Patch Information
Apple has released patched OS versions that add improved bounds checking to the affected code path. Detailed fix information is available in the vendor advisories: Apple Support Advisory #127111, Apple Support Advisory #127115, Apple Support Advisory #127116, and Apple Support Advisory #127117.
Workarounds
- No vendor-supplied workaround exists; upgrading to the patched OS version is the only supported remediation.
- Restrict app installation to vetted sources and enforce Gatekeeper and notarization checks on macOS.
- Apply principle of least functionality by removing unused apps that broaden the local attack surface.
# Verify installed macOS version meets the patched baseline
sw_vers -productVersion
# Trigger software update check on macOS
sudo softwareupdate --list
sudo softwareupdate --install --all --restart
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
