CVE-2026-86889

Certificate Validation Flaw Allowing TLS Interception by Privileged Network Attacker

Published Sep 14, 2026 CVSS 3.1 · 4.8 Medium EPSS < 1% KEV · Not listed
Description
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.

Analysis

AI-generated

Technical impact

A flaw in macOS’s certificate validation process allows an attacker positioned on a privileged network segment to intercept network traffic. This vulnerability is a certificate validation error (CWE-295) that jeopardizes confidentiality.

Affected Systems

Apple’s macOS in the Golden Gate series before version 27, Sequoia before 15.8, and Tahoe before 26.7 are affected. The issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7 and later releases.

Risk and Exploitability

The CVSS score of 4.8 indicates moderate severity, while the EPSS score of less than 1% signals a low probability of exploitation in the wild. The vulnerability is not listed in the CISA KEV catalog. Exploitation requires an attacker to already have a privileged position on the network; once that condition is met, the attacker may intercept traffic, underscoring the potential for confidential data compromise.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade to macOS Golden Gate 27, Sequoia 15.8, Tahoe 26.7, or later to apply Apple’s fix
  • Configure network devices to enforce strict certificate pinning or chain validation and reject untrusted certificates
  • Implement monitoring for abnormal TLS handshakes or certificate anomalies that may indicate a man‑in‑the‑middle attack

Generated by OpenCVE AI on September 20, 2026 at 19:47 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Certificate Validation Flaw Allowing TLS Interception by Privileged Network Attacker
Type Values Removed Values Added
Title Certificate Validation Issue Allows Traffic Interception in macOS
Type Values Removed Values Added
CPEs cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Certificate Validation Issue Allows Traffic Interception in macOS
Weaknesses CWE-295
Type Values Removed Values Added
First Time appeared Apple
Apple macos
Vendors & Products Apple
Apple macos
Type Values Removed Values Added
Description 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.
References
Weaknesses
  • CWE-295

    Improper Certificate Validation

Sources

Status
PUBLISHED
Assigner
apple
Published
Updated
Oct 26, 2026, 8:40 PM
Reserved
Sep 8, 2026, 4:43 PM
Status
Analyzed
Published
Sep 14, 2026, 9:17 PM
Modified
Sep 16, 2026, 1:03 AM