CVE-2026-25667

HIGH

.NET 8.0.0-8.0.21 and 9.0.0-9.0.10 - Uncontrolled Resource Consumption via Crafted QUIC Packet

Title source: llm

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 (3)

Core 3

Core References

https://github.com/IsaJafarov/Kestrel-DoS

View Writeup ZIP pw:eip

https://github.com/dotnet/aspnetcore/commit/96ccc40a0e095424b19506e8268b9b1a3e23d6a7#diff-667d5b3693f93a0f706ab211428998b210862f9b885d917104d2013118312626

View Patch ZIP pw:eip

https://github.com/IsaJafarov/Q3Fuzz

Scores

CVSS v3 7.5

EPSS 0.0300

EPSS Percentile 85.6%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact partial

Details

CWE

CWE-400

Status published

Products (1)

microsoft/.net 8.0.0 - 8.0.22

Published Mar 19, 2026

Tracked Since Mar 20, 2026