Unexpected System Termination in macOS via Malicious SMB Server

Publication date: 2026-09-14

Last updated on: 2026-09-14

Assigner: Apple Inc.

Description

An integer underflow was addressed with improved input validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. Connecting to a malicious SMB server may lead to unexpected system termination.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-14

Last Modified

2026-09-14

Generated

2026-09-15

AI Q&A

2026-09-15

EPSS Evaluated

N/A

NVD

CVE-2026-84536

Affected Vendors & Products

Vendor	Product	Version / Range
apple	macos	27
apple	macos	15.8
apple	macos	26.7

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability is an integer underflow issue caused by insufficient input validation. It was addressed in specific macOS versions. Exploiting it requires connecting to a malicious SMB server, which could cause the system to terminate unexpectedly.

Impact Analysis

If you connect to a malicious SMB server, your system may crash or terminate unexpectedly. This could lead to data loss or disruption of services on your device.

Mitigation Strategies

Update to macOS Golden Gate 27, macOS Sequoia 15.8, or macOS Tahoe 26.7 or later to address the integer underflow issue. Avoid connecting to untrusted SMB servers until patched.

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