CVE-2026-86871: Input Validation

Published Oct 20, 2026

Updated

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. An attacker with control of a network file server may be able to cause unexpected system termination.

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade macOS Golden Gate to a version that resolves this vulnerability.
Fixed in 27
Upgrade
Upgrade macOS Sequoia to a version that resolves this vulnerability.
Fixed in 15.8
Upgrade
Upgrade macOS Tahoe to a version that resolves this vulnerability.
Fixed in 26.7

Event History

Oct 20, 2026

CVE Published

via MITRE·12:50 AM

Data Sourced

via MITRE·12:50 AM

DescriptionWeakness

Data Sourced

via NVD·01:17 AM

Description

Frequently Asked Questions

Who can exploit this issue?

An attacker needs control of a network file server that the affected Mac accesses. The disclosed impact is unexpected system termination.

Which macOS releases contain the fix?

Apple lists fixes in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7.