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[ CVE-2026-65400 · Published 6 Aug 2026 ]

Apple macOS Improper Authentication Vulnerability

Exploited · CISA KEV CVSS 9.8 EPSS 2%No fix listed yet

[ Why it matters ]Priority signals

  • Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2026-08-18
  • Critical severity: CVSS 9.8

[ Description ]Official description

An authentication issue was addressed with improved state management. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.7.9, macOS Sonoma 14.8.9, macOS Tahoe 26.6.1, macOS Tahoe 26.7. An attacker on the network may be able to authenticate to Screen Sharing without valid credentials.

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

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 21 Aug 2026): 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.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References