CVE-2026-84543

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-14 · updated 2026-10-26
Weakness: CWE-125

Description

An out-of-bounds access issue was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. Connecting to a malicious SMB server may cause unexpected system termination or corrupt kernel memory.

Affected products

Apple macOS: from 15.0 before 15.8; from 26.0 before 26.7 — fixed in 15.8, 26.7
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; 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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