CVE-2026-100219: Microsoft QUIC Remote Code Execution Vulnerability
Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.
- Published by source
- 2026-10-13
- First seen by Reality Radar
- 2026-10-22
- Last verified
- 2026-10-22
Affected
- Manufacturer
- Microsoft
- Products
- Windows Server 2022 Windows 11 Version 23H2 Windows 11 Version 24H2 Windows 11 Version 25H2 Windows 11 Version 26H2 Windows Server 2025 Windows 11 Version 26H1 Windows 11 version 26H1
- CPE
- cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:x64:*
Whether your exact unit is affected depends on the model, serial number and region in the official notice.
What the official notice says
Risk: Critical — Remote Code Execution
Remedy / actions:
- Install the security update: https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5126655
Is this affecting you?
Add what you own or use and Reality Radar will tell you when official changes match it — with evidence and next steps.
Sources
- Microsoft Security Update Guide (MSRC) Tier A · official published 2026-10-13
Evidence ledger
Every piece of evidence we store is appended to a public hash chain, so later edits are detectable. Anyone can re-verify it.
| Entry | Kind | Observed | Evidence hash | Entry hash |
|---|---|---|---|---|
| #94 | new | 2026-10-22 | bc01f6389eae…3b0fcb | 45f79eb748ed…2ca965 |
Chain head: #1076 8ad5adc30b9b…88ce20