Apple · macOS
CVE-2026-65400
Apple macOS Improper Authentication Vulnerability
What it is
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.
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.
Deadline for US federal agencies: August 21, 2026
More exploited flaws from Apple
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Apr 17, 2023 | Use-After-Free | macOS | High 7.8 | 0.7% |
| Apr 4, 2022 | Out-of-Bounds Read | macOS | Medium 5.5 | 1.1% |
| Apr 4, 2022 | Out-of-Bounds Write | macOS | High 7.8 | 12% |
| Nov 3, 2021 | Unspecified | macOS | Medium 5.5 | 69% |
| Nov 3, 2021 | Unspecified | macOS | High 7.8 | 7.0% |
| Sep 29, 2026 | Out-of-Bounds Write | Multiple Products | High 8.8 | 26% |
| Mar 20, 2026 | Buffer Overflow | Multiple Products | High 8.8 | 1.7% |
| Mar 20, 2026 | Improper Locking | Multiple Products | High 7.8 | 0.4% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.