Actively exploited KEV catalog No authentication
CVE-2026-65400

Apple macOS Improper Authentication Vulnerability

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…

CheckOps priority index
5.8/10 Patch within 7 days
Severity9.8
Probability0.2
Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 1.7% higher than 77.5% of CVEs
CVSS 3.1 9.8 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:
Exploited for 77 days 18 Aug 2026
CISA due date 21 Aug 2026 for US federal agencies

Exploitation probability EPSS · FIRST

05010025 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

  • KEV catalog (CISA)18 Aug 2026
  • Exploited in EUVD (ENISA)18 Aug 2026
  • Used by ransomwareno
  • EPSS above 10 %1.7%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: 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.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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.

Affected products

macOS
Affected versions
  • 0 <15.7.9
  • 0 <27
  • 0 <26.6.1
  • 0 <14.8.9
  • 0 <26.7
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

References

Other exploited vulnerabilities from the same vendor

  • CVE-2026-86950Apple Multiple Products Out-of-Bounds Write Vulnerability
    6.7 · Actively exploited
  • CVE-2025-43520Apple Multiple Products Classic Buffer Overflow Vulnerability
    3.4 · Background exploitation
  • CVE-2025-43510Apple Multiple Products Improper Locking Vulnerability
    4.3 · Background exploitation
  • CVE-2025-31277Apple Multiple Products Buffer Overflow Vulnerability
    5.4 · Background exploitation
  • CVE-2023-43000Apple Multiple products Use-After-Free Vulnerability
    5.4 · Background exploitation
  • CVE-2023-41974Apple iOS and iPadOS Use-After-Free Vulnerability
    4.4 · Background exploitation

Are you affected?

CheckOps reads your SBOMs and scans, and alerts you as soon as one of your dependencies is exploited.

Get notified at launch

Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities