Risk Letters

Exploited vulnerability

CVE-2026-65400

TLP:CLEAR

Apple macOS Improper Authentication Vulnerability

Apple macOS contains an improper authentication vulnerability that could allow an attacker on the network to authenticate to Screen Sharing without valid credentials.

Facts

  • Vendor: Apple
  • Product: macOS
  • CVSS: 9.8
  • EPSS (probability of exploitation within 30 days): 1.7 %
  • On CISA's Known Exploited Vulnerabilities list since: 18 August 2026
  • First known exploitation: 18 August 2026
  • CISA's deadline for US federal agencies: 21 August 2026
  • Weakness: CWE-287
  • First seen by Risk Letters: 25 August 2026

Members see which Nordic sectors the flaw hits, and what to do about it.

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Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD