---
title: "CVE-2026-84515: Apple macOS - Out of Bounds Write"
description: "Apple macOS Golden Gate 27, Sequoia 15.8, and Tahoe 26.7 contain an out-of-bounds write caused by insufficient bounds checking in SMB client, letting attackers cause kernel memory corruption by connecting to a malicious SMB server."
url: https://panop.io/threat-heartbeat/CVE-2026-84515/
---

# CVE-2026-84515 Apple macOS - Out of Bounds Write

Apple macOS Golden Gate 27, Sequoia 15.8, and Tahoe 26.7 contain an out-of-bounds write caused by insufficient bounds checking in SMB client, letting attackers cause kernel memory corruption by connecting to a malicious SMB server.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.17% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-84515)

## Details

Type

Out of Bounds Write

Impact

Denial Of Service, Privilege Escalation

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

14 September 2026

Updated

15 October 2026

Weakness

[CWE-787](https://cwe.mitre.org/data/definitions/787.html)

## Vendor fix

Update to macOS Golden Gate 27, Sequoia 15.8, Tahoe 26.7 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-84515](https://nvd.nist.gov/vuln/detail/CVE-2026-84515)
- [https://support.apple.com/en-us/149042](https://support.apple.com/en-us/149042)
- [https://support.apple.com/en-us/149043](https://support.apple.com/en-us/149043)
- [https://support.apple.com/en-us/149035](https://support.apple.com/en-us/149035)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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