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High MSRC-CVE-2026-21219 1 CVE

Inbox COM Objects (Global Memory) Remote Code Execution Vulnerability

Published Jan 13, 2026 · Updated Jan 13, 2026

Summary

Impact: Remote Code Execution. Microsoft rating: Important. Not known to be exploited — Exploitation Unlikely. Customer action: Required.

Details

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
Successful exploitation of this vulnerability requires an attacker to win a race condition.

According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution?
The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. This means an attacker or victim needs to execute code from the local machine to exploit the vulnerability.

According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?
An attacker must send a user a malicious Office file and convince them to open it.

Security updates
10.0.26100.7463 — https://learn.microsoft.com/en-us/windows/apps/windows-sdk/release-notes

Vulnerabilities 1

  • High 7.0

    Inbox COM Objects (Global Memory) Remote Code Execution Vulnerability

    Use after free in Inbox COM Objects allows an unauthorized attacker to execute code locally.

Revision history

  1. #1

    Information published.

References