Microsoft QUIC Security Feature Bypass Vulnerability

Summary

Insecure default variable initialization in Microsoft QUIC allows an unauthorized attacker to bypass a security feature over a network.

Remediation

1. Inventory every Microsoft Windows 11 version 23H2 deployment, including staging.
2. Upgrade Microsoft Windows 11 version 23H2 to the fixed version for your release line, listed under Affected versions.
3. Confirm the running version after the upgrade.

References

• Patchhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-103577