CVE-2026-65400: Apple MacOS

What is CVE-2026-65400?

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.

CVSS9.8 NVD 3.1

SeverityCRITICAL

Exploitation In the wild In CISA KEV

EPSS<1% · P40

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD published2026-08-06

NVD last modified2026-08-19

Timeline

2026-08-06Published to the U.S. National Vulnerability Database (NVD)
2026-08-18Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-08-19NVD record last updated
2026-08-21CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

Apple macOS Improper Authentication Vulnerability

Added to KEV2026-08-18

Federal patch deadline2026-08-21

Known ransomware useUnknown

Affected product

Apple MacOS

Remediation Steps

Apply the vendor security update for Apple macOS as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 3 of August 2026 (August 17 – 23)

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🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.