August 18, 2026 · Applied Cybernetics Group
CVE-2026-65400 — Apple macOS
Apple macOS Improper Authentication Vulnerability
- Added to KEV
2026-08-18- Federal due date
2026-08-21- Vendor
- Apple
- Product
- macOS
- EPSS
- 95.5th percentile (score 0.105, as of
2026-09-16) - NVD CVSS v3.1
- 9.8 (CRITICAL)
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2026-65400
CISA short 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.
NVD 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.