CVE WatchAug 19, 2026

CVE-2026-65400

Apple macOS Improper Authentication Vulnerability

CVSS

9.8

Critical

EPSS

9.9%

p95

KEV

YES

Aug 18, 2026

Exploit Today

0-100

Published: Aug 6, 2026 · Last modified: Aug 19, 2026 · CWE-287

EPSS · 30d

0.3%EPSS · 30 days10.4%

2026-08-072026-08-30

KEV catalog record

Product

Apple / macOS

Vulnerability

Apple macOS Improper Authentication Vulnerability

Added to KEV

Aug 18, 2026

Remediate by

Aug 21, 2026

Known ransomware use

Summary description

Apple macOS contains an improper authentication vulnerability that could allow an attacker on the network to authenticate to Screen Sharing without valid credentials.

Required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Notes

https://support.apple.com/en-us/148170; https://support.apple.com/en-us/148171; https://support.apple.com/en-us/148172 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-65400

Technical description

An authentication issue was addressed with improved state management. This issue is fixed in macOS Sequoia 15.7.9, macOS Sonoma 14.8.9, macOS Tahoe 26.6.1. An attacker on the network may be able to authenticate to Screen Sharing without valid credentials.

Official references

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