CVE-2026-66563 WordPress Windsor theme <= 2.10 - PHP Object Injection vulnerability

Critical 9.8 Published Updated

Unauthenticated attackers can exploit PHP object injection in the Windsor theme to potentially execute arbitrary code.

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-2026-66563?

CVE-2026-66563 is a critical unsafe deserialization vulnerability in ThemeREX Windsor, published on 10 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Unauthenticated PHP Object Injection in Windsor <= 2.10 versions.

Weakness: CWE-502

Which versions are affected by CVE-2026-66563?

How do I fix CVE-2026-66563?

No fix has been published for CVE-2026-66563 yet. Limit exposure of the affected software until one is available.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2026-66563 being exploited?

There is no known exploitation of CVE-2026-66563 in the wild and no public exploit code.

Sources

Also known as GHSA-vfx8-984f-hxhg.

Is CVE-2026-66563 in your software?

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