What is CVE-2026-84567?

CVE-2026-84567 is a medium-severity vulnerability in Apple macOS, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.5/10. Published 2026-09-14.

How severe is CVE-2026-84567?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Apple macOS

CVE-2026-84567

The issue was addressed with improved memory handling. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An app may be able to cause unexpected system termination.

Vulnerability class: Buffer Overflow

Published 2026-09-14 · last modified 2026-09-18.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (5.1th percentile), scored 2026-10-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Apple macOS

Weakness classification (CWE)

References

support.apple.com/en-us/149035 (Release Notes, Vendor Advisory)
support.apple.com/en-us/149042 (Release Notes, Vendor Advisory)
support.apple.com/en-us/149043 (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2026-84567?: CVE-2026-84567 is a medium-severity vulnerability in Apple macOS, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.5/10. Published 2026-09-14.
How severe is CVE-2026-84567?: Medium severity. CVSS v3 base score is 5.5 out of 10.