CVE-2026-43776: Apple iPadOS Buffer Overflow Vulnerability

CVE-2026-43776 Overview

CVE-2026-43776 is a buffer overflow vulnerability affecting Apple iOS, iPadOS, and macOS. The flaw stems from insufficient bounds checking when the operating system processes a maliciously crafted file. Successful exploitation can lead to unexpected application termination or arbitrary code execution in the context of the affected process.

Apple addressed the issue in iOS 26.6, iPadOS 26.6, macOS Sequoia 15.7.8, and macOS Tahoe 26.6. The vulnerability is categorized under [CWE-120] (Classic Buffer Overflow) and requires local access with user interaction to trigger.

Critical Impact
Processing a maliciously crafted file may lead to unexpected app termination or arbitrary code execution on affected Apple devices.

Affected Products

Apple iOS (versions prior to 26.6)
Apple iPadOS (versions prior to 26.6)
Apple macOS Sequoia (prior to 15.7.8) and macOS Tahoe (prior to 26.6)

Discovery Timeline

2026-07-27 - CVE-2026-43776 published to NVD
2026-07-28 - Last updated in NVD database

Technical Details for CVE-2026-43776

Vulnerability Analysis

The vulnerability is a classic buffer overflow in file-parsing logic within Apple operating systems. When the affected component processes an attacker-controlled file, it fails to properly validate input boundaries before copying data into a fixed-size buffer. The overflow condition allows adjacent memory regions to be corrupted.

An attacker who supplies a specially crafted file can trigger memory corruption during parsing. Depending on the memory layout and the data written past the buffer boundary, this can result in application crash or execution of attacker-controlled code. Apple's advisory confirms the fix relies on improved bounds checking within the vulnerable routine.

Exploitation requires the victim to open or process the malicious file, aligning with the user interaction requirement. Because the attack surface is local file handling, delivery mechanisms include email attachments, downloaded content, messaging apps, and removable media.

Root Cause

The root cause is missing or insufficient length validation before a memory copy operation during file parsing. When user-supplied file data exceeds the destination buffer size, the write operation extends beyond allocated memory, corrupting adjacent stack or heap structures.

Attack Vector

The attack vector is local and requires user interaction. An attacker crafts a malicious file and delivers it to the target through any channel that results in the file being opened by a vulnerable Apple component. Once processed, the overflow condition triggers, and the attacker gains the ability to influence process execution flow.

No verified public exploit code is available for this issue. The vulnerability mechanism is described in prose based on Apple's advisory content, as no proof-of-concept has been released. Refer to the Apple Support Article 128066, Apple Support Article 128067, and Apple Support Article 128071 for vendor guidance.

Detection Methods for CVE-2026-43776

Indicators of Compromise

Unexpected crashes of file-handling applications on iOS, iPadOS, or macOS devices, particularly when opening files received from untrusted sources.
Crash reports referencing memory access violations or stack corruption in file-parsing components.
Unusual child process creation following the opening of documents, images, or media files.

Detection Strategies

Monitor endpoint telemetry for abnormal termination of built-in Apple applications tied to file parsing.
Correlate file-open events with subsequent anomalous behavior such as network callbacks or unexpected process spawns.
Inspect crash logs on managed macOS fleets for signatures consistent with buffer overflow conditions.

Monitoring Recommendations

Ingest macOS ReportCrash and unified log data into a centralized SIEM for correlation with file-download events.
Track OS version compliance across mobile device management (MDM) inventories to identify unpatched endpoints.
Alert on execution chains where a document-viewing process spawns shells, scripting interpreters, or network utilities.

How to Mitigate CVE-2026-43776

Immediate Actions Required

Update all affected Apple devices to iOS 26.6, iPadOS 26.6, macOS Sequoia 15.7.8, or macOS Tahoe 26.6 without delay.
Enforce OS version compliance through MDM policies and block non-compliant devices from accessing sensitive resources.
Instruct users to avoid opening files from untrusted senders until patches are applied.

Patch Information

Apple released fixes in iOS 26.6, iPadOS 26.6, macOS Sequoia 15.7.8, and macOS Tahoe 26.6. Full patch details are available in Apple Support Article 128066, Apple Support Article 128067, and Apple Support Article 128071. Apply the vendor updates through the standard software update mechanism.

Workarounds

Restrict file transfers from untrusted sources through email gateway and web proxy filtering.
Disable automatic previews of attachments and downloaded files where configuration options permit.
Segment users on unpatched devices from sensitive systems until the update is deployed.

bash

# Verify macOS version to confirm patch status
sw_vers -productVersion

# Trigger a software update check on macOS
sudo softwareupdate --list
sudo softwareupdate --install --all --restart