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Fencer Vulns
medium 5.9

CVE-2026-69304 json

ASP.NET Core Denial of Service Vulnerability

published 2026-09-08 2 mo ago modified 2026-10-31 8 d ago also BIT-aspnet-core-2026-69304 , BIT-dotnet-2026-69304 , BIT-dotnet-sdk-2026-69304 , EUVD-2026-73741 , GHSA-8cp2-47hg-mfgh

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

Improper handling of highly compressed data (data amplification) in ASP.NET Core allows an unauthorized attacker to deny service over a network.

Patch / fix

  • nuget Microsoft.AspNetCore.Server.IISIntegration 8.0.31, 9.0.20, 10.0.12, 11.0.0-rc.1
  • bitnami aspnet-core 8.0.28, 9.0.17, 10.0.9
  • bitnami dotnet 8.0.31, 9.0.20, 10.0.12
  • bitnami dotnet-sdk 8.0.31, 9.0.20, 10.0.12
  • Microsoft .NET 10.0 runtime 10.0.12
  • Microsoft .NET 8.0 runtime 8.0.31
  • Microsoft .NET 9.0 runtime 9.0.20
  • Microsoft ASP.NET Core 10.0 10.0.12
  • Microsoft ASP.NET Core 11.0 11.0 RC1
  • Microsoft ASP.NET Core 8.0 8.0.31
  • Microsoft ASP.NET Core 9.0 9.0.20
  • Microsoft Microsoft Visual Studio 2022 version 17.14 17.14.40
  • Microsoft Microsoft Visual Studio 2026 version 18.9 18.9.3
  • dotnet8.0 hummingbird 1 8.0.130-0.2.hum1
  • dotnet-sdk-8.0 hummingbird 1 8.0.130-0.2.hum1
  • dotnet-hostfxr-8.0 hummingbird 1 8.0.30-0.2.hum1
  • dotnet-runtime-8.0 hummingbird 1 8.0.30-0.2.hum1
  • dotnet-sdk-dbg-8.0 hummingbird 1 8.0.130-0.2.hum1
  • dotnet-templates-8.0 hummingbird 1 8.0.130-0.2.hum1
  • aspnetcore-runtime-8.0 hummingbird 1 8.0.30-0.2.hum1
  • dotnet-runtime-dbg-8.0 hummingbird 1 8.0.30-0.2.hum1

red hat advisories RHSA-2026:74950RHSA-2026:74947RHSA-2026:66863

  • dotnet8-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 8.0.31-r0
  • dotnet9-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 9.0.20-r0
  • dotnet10-runtime Alpine 3.23 10.0.13-r0
  • dotnet10-runtime Alpine 3.24 10.0.12-r0

alpine advisories ALPINE-CVE-2026-69304

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-69304 updated cvss 5.9

dotnet: ASP.NET Core: Denial of Service via Data Amplification

  • Red Hat Hardened Images dotnet10.0 10.0.112-1.hum1, dotnet8.0 8.0.130-0.2.hum1, dotnet9.0 9.0.119-2.1.hum1, dotnet-sdk-10.0 10.0.112-1.hum1, dotnet-sdk-8.0 8.0.130-0.2.hum1, dotnet-sdk-9.0 9.0.119-2.1.hum1, +28 more
    fixed: vendor fix RHSA-2026:74950
  • Red Hat Hardened Images dotnet-host 10.0.12-1.hum1, dotnet-hostfxr-10.0 10.0.12-1.hum1, dotnet-runtime-10.0 10.0.12-1.hum1, aspnetcore-runtime-10.0 10.0.12-1.hum1, dotnet-runtime-dbg-10.0 10.0.12-1.hum1, dotnet-apphost-pack-10.0 10.0.12-1.hum1, +3 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.85% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
GitHub 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
nuget Microsoft.AspNetCore.Server.IISIntegration
>=11.0.0-preview.1, <11.0.0-rc.1
>=8.0.0, <8.0.31
>=9.0.0, <9.0.20
>=10.0.0, <10.0.12
11.0.0-rc.1
8.0.31
9.0.20
10.0.12
bitnami aspnet-core
>=8.0.0, <8.0.28
>=9.0.0, <9.0.17
>=10.0.0, <10.0.9
8.0.28
9.0.17
10.0.9
bitnami dotnet
>=8.0.0, <8.0.31
>=9.0.0, <9.0.20
>=10.0.0, <10.0.12
8.0.31
9.0.20
10.0.12
bitnami dotnet-sdk
>=8.0.0, <8.0.31
>=9.0.0, <9.0.20
>=10.0.0, <10.0.12
8.0.31
9.0.20
10.0.12

Affected products

  • Microsoft .NET 10.0 runtime
  • Microsoft .NET 8.0 runtime
  • Microsoft .NET 9.0 runtime
  • Microsoft ASP.NET Core 10.0
  • Microsoft ASP.NET Core 11.0
  • Microsoft ASP.NET Core 8.0
  • Microsoft ASP.NET Core 9.0
  • Microsoft Microsoft Visual Studio 2022 version 17.14
  • Microsoft Microsoft Visual Studio 2026 version 18.9

Classification

Weakness
  • CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.