---
id: CVE-2026-84536
title: An integer underflow was addressed with improved input validation
summary: >-
  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.
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-190
vendor: apple
product: macos
affected:
  - 'macos >= 15.0, < 15.8'
  - 'macos >= 26.0, < 26.7'
patched:
  - macos 26.7
published: '2026-09-14'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T18:02:20.767'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84536'
references:
  - url: 'https://support.apple.com/en-us/149035'
    label: product-security@apple.com
  - url: 'https://support.apple.com/en-us/149042'
    label: product-security@apple.com
  - url: 'https://support.apple.com/en-us/149043'
    label: product-security@apple.com
tags:
  - nvd
  - cve.org
epss: 0.00404
epssPercentile: 0.31805
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T16:43:25.347583Z'
ingestedAt: '2026-09-14T21:15:17.540Z'
---

## Overview

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.

## Affected

- `macos >= 15.0, < 15.8`
- `macos >= 26.0, < 26.7`

## Remediation

Upgrade past the affected range:

- `macos 26.7`