CVE-2026-65400

Apple macOS Improper Authentication Vulnerability

  • Critical 9.8
  • Exploited: added to CISA KEV 18 Aug 2026

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.

Key facts

Published
6 Aug 2026
Last changed
26 Oct 2026
Assigned by
apple
KEV added
18 Aug 2026
KEV fix due
21 Aug 2026
EPSS
18.057% likely to be exploited in the next 30 days, higher than 97.242% of CVEs (scores for 15 Nov 2026)
SSVC (CISA)
Exploitation: active; Automatable: yes; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 9.8CVSS 3.1, Criticalfrom CISA (ADP container)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What to do

  • 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.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
ApplemacOS
  • 0 up to but excluding 14.8.9 (affected)
  • 0 up to but excluding 15.7.9 (affected)
  • 0 up to but excluding 26.6.1 (affected)
  • 0 up to but excluding 26.7 (affected)
  • 0 up to but excluding 27 (affected)

Timeline

  1. 6 Aug 2026 Published
  2. 18 Aug 2026 CVE-2026-65400 added to CISA KEV
  3. 18 Aug 2026 Added to the CISA KEV catalogue

Weakness

References