CVE-2026-84536

Undergoing Analysis Undergoing Analysis - In Progress

Unexpected System Termination in macOS via Malicious SMB Server

Publication date: 2026-09-14

Last updated on: 2026-09-15

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

2026-09-15

Generated

2026-10-05

AI Q&A

2026-09-15

EPSS Evaluated

2026-10-04

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-190	The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

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.

Detection Guidance

This vulnerability is related to an integer underflow in SMB server handling on Apple macOS systems. Detection primarily involves checking the macOS version against the patched releases (macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7). Use the command 'sw_vers' to check your current macOS version.

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.

Compliance Impact

The provided CVE data does not specify any direct impact on compliance with standards like GDPR or HIPAA. The vulnerability involves an integer underflow in macOS leading to unexpected system termination when connecting to a malicious SMB server, but no compliance implications are mentioned.

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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