CVE-2026-65400
Improper Authentication in Apple macOS. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 18 August 2026.
- Product
- Apple macOS
- Added to CISA's catalog
- Federal fix-by date
- Ransomware
- No known use in ransomware campaigns
- Vendor advisories
- Sources
- CISA’s catalog, NVD entry
CISA’s description.
Apple macOS contains an improper authentication vulnerability that could allow an attacker on the network to authenticate to Screen Sharing without valid credentials.
More from Apple this year.
- CVE-2024-27834 Improper Authentication, added
- CVE-2026-86950 Out-of-Bounds Write, added
- CVE-2025-43520 Classic Buffer Overflow, added
- CVE-2025-43510 Improper Locking, added
- CVE-2025-31277 Buffer Overflow, added
- CVE-2023-43000 Use-After-Free, added
- CVE-2023-41974 Use-After-Free, added
- CVE-2021-30952 Integer Overflow or Wraparound, added
Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.