CVE-2026-62815: Microsoft QUIC Remote Code Execution Vulnerability

Published Aug 11, 2026
·
Updated

Microsoft QUIC Remote Code Execution Vulnerability

Other sources

Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.

— Microsoft

Affected Software

12 affected componentsFixes available
Microsoft Windows Server 2025<10.0.26100.33296, <10.0.26100.33222
10.0.26100.3329610.0.26100.33222
Microsoft Windows 11=25H2
10.0.26200.916810.0.26100.9106
Microsoft Windows 11=25H2
10.0.26200.916810.0.26100.9106
Microsoft Windows 11=26H1
10.0.28000.2704
Microsoft Windows 11=26H1
10.0.28000.2704
Microsoft Windows Server 2022<10.0.20348.5499, <10.0.20348.5440
10.0.20348.549910.0.20348.5440
Microsoft Windows 11=24H2
10.0.26100.916810.0.26000.9106
Microsoft Windows 11=24H2
10.0.26100.916810.0.26100.9106
Microsoft Windows 11=23H2
10.0.22631.7517
Microsoft Windows 11=23H2
10.0.22631.7517
Microsoft Windows Server 2025<10.0.26100.33296, <10.0.26100.33222
10.0.26100.3329610.0.26100.33222
Microsoft Windows Server 2022<10.0.20348.5499, <10.0.20348.5440
10.0.20348.549910.0.20348.5440

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26100.33296Fixed in 10.0.26100.33222Patch KB5120228
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26200.9168Fixed in 10.0.26100.9106Patch KB5120994
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.28000.2704Patch KB5121000
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.20348.5499Fixed in 10.0.20348.5440Patch KB5120229
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26100.9168Fixed in 10.0.26100.9106Patch KB5120994
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26100.9168Fixed in 10.0.26000.9106Patch KB5120994
  7. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.22631.7517Patch KB5120240

Event History

Aug 11, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:04 PM
Data Sourced
via MITRE·05:04 PM
DescriptionSeverity
Data Sourced
via NVD·05:18 PM
DescriptionSeverityWeakness
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Frequently Asked Questions

1

What is the severity of CVE-2026-62815?

CVE-2026-62815 has a critical severity rating of 9.8.

2

How can I mitigate CVE-2026-62815?

To mitigate CVE-2026-62815, ensure that your Microsoft Windows systems are updated with the latest security patches.

3

What systems are affected by CVE-2026-62815?

CVE-2026-62815 affects Microsoft Windows 11, Windows Server 2025, and Windows Server 2022.

4

What type of vulnerability is CVE-2026-62815?

CVE-2026-62815 is classified as a Use After Free vulnerability which can lead to remote code execution.

5

What impact does CVE-2026-62815 have on affected systems?

CVE-2026-62815 allows unauthorized attackers to execute code remotely on affected systems over a network.

Company

Resources

Contact

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