CVE-2026-39873 Memory corruption in macOS

Critical 9.8 Published 27 Jul 2026 Updated 28 Jul 2026

A memory handling flaw in macOS allows a malicious SMB server to cause unexpected system termination, requiring users to apply security updates.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-39873?

CVE-2026-39873 is a critical memory corruption vulnerability in Apple Macos, published on 27 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. Connecting to a malicious SMB server may lead to unexpected system termination.

Weakness: CWE-119

Which versions are affected by CVE-2026-39873?

It affects 1 product.

Products include Apple Macos.

How do I fix CVE-2026-39873?

No fix has been published for CVE-2026-39873 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-39873 being exploited?

There is no known exploitation of CVE-2026-39873 in the wild and no public exploit code.

All Apple Macos vulnerabilities

Sources

Also known as GHSA-2pcr-98qw-8jgc.