Microsoft QUIC Remote Code Execution Vulnerability

Date Oct 13, 2026

Type Patch Tuesday

Signal Critical vendor advisory

Vendor / Product Microsoft · Microsoft QUIC

CVE CVE-2026-100219

Critical vendor advisory CVE-2026-100219

Summary

Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network. Published in October 2026 Security Updates. MSRC exploitability: Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely.

Why it matters

Microsoft published this item through its Security Update Guide, making it part of Patch Tuesday triage for affected Windows, cloud, or application estates. EPSS percentile: 62%.

Operator check

Review the Microsoft Security Update Guide entry for CVE-2026-100219. Confirm whether Microsoft QUIC is deployed, then apply the current security update or documented mitigation. CVSS score: 9.8. EPSS probability: 1.0%; percentile: 62%.

Sources

MSRC 2026-Oct Security Update Guide NVD — CVE-2026-100219 Source reference

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.

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