CVE-2026-62815

CRITICALCVSS 9.8/10

Last modified

CVE-2026-62815 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network..

Description

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

Metrics

CVSS 3.1
9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
MicrosoftWindows 11 version 23H2>= 10.0.22631.0, < 10.0.22631.7517
MicrosoftWindows 11 Version 23H2>= 10.0.22631.0, < 10.0.22631.7517
MicrosoftWindows 11 Version 24H2>= 10.0.26100.0, < 10.0.26100.9168
MicrosoftWindows 11 Version 25H2>= 10.0.26200.0, < 10.0.26200.9168
MicrosoftWindows 11 version 26H1>= 10.0.28000.0, < 10.0.28000.2704
MicrosoftWindows Server 2022>= 10.0.20348.0, < 10.0.20348.5499
MicrosoftWindows Server 2025>= 10.0.26100.0, < 10.0.26100.33296
MicrosoftWindows Server 2025 (Server Core installation)>= 10.0.26100.0, < 10.0.26100.33296

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-62815?
Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.
How severe is CVE-2026-62815?
CVE-2026-62815 has a CVSS score of 9.8/10 (CRITICAL severity).
How do I fix CVE-2026-62815?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST