CVE-2026-21219 Inbox COM Objects (Global Memory) Remote Code Execution Vulnerability
An attacker can execute code locally via a use-after-free vulnerability in Windows SDK Inbox COM Objects.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-21219?
CVE-2026-21219 is a high-severity use after free vulnerability in Microsoft Windows SDK, published on 13 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Use after free in Inbox COM Objects allows an unauthorized attacker to execute code locally.
Weakness: CWE-416
Which versions are affected by CVE-2026-21219?
It affects 1 product.
Products include Microsoft Windows Software Development Kit.
How do I fix CVE-2026-21219?
No fix has been published for CVE-2026-21219 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-21219 being exploited?
There is no known exploitation of CVE-2026-21219 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows SDK
Sources
Also known as GHSA-wvh3-vgpw-w4mr.