CVE-2026-43677 Memory corruption in macOS

Medium 6.5 Published Updated

An out-of-bounds write in macOS allows a malicious WebDAV server to cause unexpected app termination.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2026-43677?

CVE-2026-43677 is a medium-severity memory corruption vulnerability in Apple Macos, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

An out-of-bounds write issue was addressed by removing the vulnerable code. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. Connecting to a malicious WebDAV server may lead to unexpected app termination.

Weakness: CWE-787

Which versions are affected by CVE-2026-43677?

It affects 1 product.

Products include Apple Macos.

How do I fix CVE-2026-43677?

No fix has been published for CVE-2026-43677 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-2026-43677 being exploited?

There is no known exploitation of CVE-2026-43677 in the wild and no public exploit code.

All Apple Macos vulnerabilities

Sources

Also known as GHSA-vmpg-5m9v-32v3.

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