Question 1

What is CVE-2026-65400?

Accepted Answer

It is a flaw in the Secure Remote Password authentication used by macOS Screen Sharing that lets a network attacker gain access without valid credentials, enabling pre-authentication remote code execution on all supported macOS versions, according to Huntress.

Question 2

Which macOS versions are patched against it?

Accepted Answer

Apple fixed the flaw on August 6, 2026 in macOS Tahoe 26.6.1, Sequoia 15.7.9 and Sonoma 14.8.9; earlier builds remain vulnerable.

Question 3

What were attackers doing with the compromised Macs?

Accepted Answer

According to the Netherlands' NCSC, attackers reached Macs with port 5900 exposed to the internet, took full root control, and installed Monero mining software to profit from the stolen computing power.

Huntress

CISA rerates macOS Screen Sharing flaw to 9.8 after Monero-mining attacks

One sharp brief.
Every day.

Huntress

CISA rerates macOS Screen Sharing flaw to 9.8 after Monero-mining attacks

One sharp brief.Every day.

One sharp brief.
Every day.