Is CVE-2026-25667 actively exploited?

CVE-2026-25667 has no public evidence of in-the-wild exploitation as of 2026-03-24.

What is the CVSS score for CVE-2026-25667?

CVE-2026-25667 has a CVSS score of 7.5 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

How do I patch CVE-2026-25667?

Patch guidance is available from Microsoft security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-25667.

Which products are affected by CVE-2026-25667?

1 product: Microsoft Awaiting Analysis.

Fix CVE-2026-25667 - HIGH Microsoft Awaiting Analysis

Description

ASP.NET Core Kestrel in Microsoft .NET 8.0 before 8.0.22 and .NET 9.0 before 9.0.11 allows a remote attacker to cause excessive CPU consumption by sending a crafted QUIC packet, because of an incorrect exit condition for HTTP/3 Encoder/Decoder stream processing.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high
Weaknesses: CWE-400

Metadata

Primary Vendor: MICROSOFT
Published: 3/19/2026
Last Modified: 3/24/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

CVE-2026-25667

Description

CVSS Metrics

Metadata

Affected Products

Remediation Guidance

Executive Summary