CVE-2026-25667

Denial of Service via crafted QUIC packet in ASP.NET Core Kestrel

Published Mar 19, 2026 CVSS 3.1 · 7.5 High EPSS 3.2% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Denial of Service via crafted QUIC packet in ASP.NET Core Kestrel
Type Values Removed Values Added
Title Remote Denial of Service via Crafted QUIC Packet in ASP.NET Core Kestrel
Type Values Removed Values Added
Title Remote Denial of Service via Crafted QUIC Packet in ASP.NET Core Kestrel
Type Values Removed Values Added
Title Remote Denial of Service Due to Improper QUIC Exit Condition in ASP.NET Core Kestrel
Type Values Removed Values Added
Title Remote Denial of Service Due to Improper QUIC Exit Condition in ASP.NET Core Kestrel
Type Values Removed Values Added
Title Remote DoS via Crafted QUIC Packet in ASP.NET Core Kestrel
Type Values Removed Values Added
Title Remote DoS via Crafted QUIC Packet in ASP.NET Core Kestrel
Type Values Removed Values Added
Title Denial of Service via Crafted QUIC Packet in ASP.NET Core Kestrel
Type Values Removed Values Added
First Time appeared Microsoft .net
CPEs cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
Vendors & Products Microsoft .net
Type Values Removed Values Added
Title Denial of Service via Crafted QUIC Packet in ASP.NET Core Kestrel
Type Values Removed Values Added
Weaknesses CWE-400
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Microsoft
Microsoft aspnetcore
Vendors & Products Microsoft
Microsoft aspnetcore
Type Values Removed Values Added
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.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Apr 29, 2026, 2:34 PM
Reserved
Feb 4, 2026, 12:00 AM
Status
Modified
Published
Mar 19, 2026, 7:16 PM
Modified
Jun 17, 2026, 10:25 AM