What is CVE-2026-65396?

CVE-2026-65396 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 2026-10-20.

How severe is CVE-2026-65396?

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

Buffer overflow in Apple macOS

CVE-2026-65396

A buffer overflow was addressed with improved size validation. 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 2026-10-20 · last modified 2026-10-20.

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

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Apple macOS

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Frequently asked questions

What is CVE-2026-65396?: CVE-2026-65396 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 2026-10-20.
How severe is CVE-2026-65396?: Medium severity. CVSS v3 base score is 5.5 out of 10.