What is CVE-2026-86889?

CVE-2026-86889 is a medium-severity vulnerability in Apple macOS, classified under Improper Certificate Validation. CVSS score: 4.8/10. Published 2026-09-14.

How severe is CVE-2026-86889?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Vulnerability in Apple macOS

CVE-2026-86889

A certificate validation issue was addressed with improved certificate validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An attacker in a privileged network position may be able to intercept network traffic.

Vulnerability class: Improper Certificate Validation

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Apple Macos

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

product-security@apple.com
product-security@apple.com
product-security@apple.com

Frequently asked questions

What is CVE-2026-86889?: CVE-2026-86889 is a medium-severity vulnerability in Apple macOS, classified under Improper Certificate Validation. CVSS score: 4.8/10. Published 2026-09-14.
How severe is CVE-2026-86889?: Medium severity. CVSS v3 base score is 4.8 out of 10.