What’s Vulnerable › Vulnerabilities

CVE-2026-86871

• Severity: medium (CVSS 5.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-20 · updated 2026-10-26
• Weakness: CWE-20

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

Affected products

• Apple macOS: before 15.8; before 26.7; before 27 — fixed in 15.8, 26.7, 27

How to fix

Upgrade to a fixed version: Apple macOS 15.8, 26.7, 27. Check the vendor advisory for mitigations.

References

• https://support.apple.com/en-us/149035
• https://support.apple.com/en-us/149042
• https://support.apple.com/en-us/149043

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