What is CVE-2026-21219?

CVE-2026-21219 is a high-severity vulnerability in Microsoft Windows Sdk, classified under Use After Free. CVSS score: 7.0/10. Published 2026-01-13.

How severe is CVE-2026-21219?

High severity. CVSS v3 base score is 7.0 out of 10.

Use After Free in Microsoft Windows Sdk

CVE-2026-21219

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

Vulnerability class: Use-After-Free

Published 2026-01-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (29.2th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Microsoft Windows Sdk — versions 26100
Microsoft Windows Software Development Kit

Weakness classification (CWE)

CWE-416 — Use After Free

References

Inbox COM Objects (Global Memory) Remote Code Execution Vulnerability (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-21219?: CVE-2026-21219 is a high-severity vulnerability in Microsoft Windows Sdk, classified under Use After Free. CVSS score: 7.0/10. Published 2026-01-13.
How severe is CVE-2026-21219?: High severity. CVSS v3 base score is 7.0 out of 10.