High
Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-25667
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 14:13 UTC · Revision 1
Source evidence
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.
osv:CVE-2026-25667
Complete source record
{
"id": "c1529e6c65d44c68c71e5597ce7c0cd850d241c00ff4ed059ea928a6b5b966b3",
"url": "https://osv.dev/vulnerability/CVE-2026-25667",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2026-25667",
"summary": "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.",
"evidence": "osv:CVE-2026-25667",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-25667",
"aliases": [
"BIT-dotnet-2026-25667",
"BIT-dotnet-sdk-2026-25667",
"CVE-2026-25667"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/dotnet/aspnetcore",
"type": "GIT",
"events": [
{
"introduced": "3f1acb59718cadf111a0a796681e3d3509bb3381"
},
{
"fixed": "ee417479933278bb5aadc5944706a96b5ef74a5d"
},
{
"introduced": "af22effae4069a5dfb9b0735859de48820104f5b"
},
{
"fixed": "d3aba8fe1a0d0f5c145506f292b72ea9d28406fc"
},
{
"fixed": "96ccc40a0e095424b19506e8268b9b1a3e23d6a7"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "8.0"
},
{
"fixed": "8.0.22"
}
],
"source": "DESCRIPTION"
},
{
"range": [
{
"introduced": "9.0"
},
{
"fixed": "9.0.11"
}
],
"source": "DESCRIPTION"
},
{
"range": [
{
"fixed": "96ccc40a0e095424b19506e8268b9b1a3e23d6a7"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
},
{
"repo": "https://github.com/dotnet/core",
"type": "GIT",
"events": [
{
"introduced": "d78b3180414d35d6c7d136db753474e2ae2b33df"
},
{
"fixed": "0e06b3b745aaf3f2f96e5f163773d20f8c7f7f50"
},
{
"introduced": "e18becd6171b8eb0eb4ec7ea8a0280cacfcee36b"
},
{
"fixed": "0e06b3b745aaf3f2f96e5f163773d20f8c7f7f50"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "8.0.0"
},
{
"fixed": "8.0.22"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "9.0.0"
},
{
"fixed": "9.0.11"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v8.0.21",
"v8.0.20",
"v8.0.19",
"v8.0.18",
"v8.0.17",
"v8.0.16",
"v8.0.15",
"v8.0.14",
"v8.0.13",
"v8.0.12",
"v8.0.11",
"v8.0.10",
"v8.0.8",
"v8.0.7",
"v8.0.5",
"v8.0.4",
"v8.0.3",
"v8.0.2",
"v8.0.1",
"v8.0.0",
"v9.0.10",
"v10.0.0-rc.2",
"v9.0.9",
"v10.0.0-rc.1",
"v10.0.0-preview.7",
"v9.0.8",
"v10.0.0-preview.6",
"v9.0.7",
"v9.0.6",
"v10.0.0-preview.5",
"v9.0.5",
"v10.0.0-preview.4",
"v10.0.0-preview.3",
"v9.0.4",
"v10.0.0-preview.2",
"v9.0.3",
"v10.0.0-preview.1",
"v9.0.2",
"v9.0.1",
"v9.0.0",
"v6.0.36"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25667.json"
}
}
],
"modified": "2026-10-28T02:30:29.217345923Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25667.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-25667",
"https://github.com/dotnet/aspnetcore/commit/96ccc40a0e095424b19506e8268b9b1a3e23d6a7#diff-667d5b3693f93a0f706ab211428998b210862f9b885d917104d2013118312626",
"https://github.com/IsaJafarov/Kestrel-DoS",
"https://github.com/IsaJafarov/Q3Fuzz"
],
"provider_metadata": {
"cna_assigner": "mitre",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25667.json"
}
},
"related_cves": [
{
"value": "CVE-2026-25667",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 496281,
"published_at": "2026-03-19T00:00:00+00:00"
}