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Fencer Vulns
critical 9.9

CVE-2025-55315 in the critical feed json

ASP.NET Security Feature Bypass Vulnerability

published 2025-10-14 12 mo ago modified 2026-10-18 21 d ago also BIT-aspnet-core-2025-55315 , EUVD-2025-34426 , GHSA-5rrx-jjjq-q2r5

cvss
9.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
67.2%
EPSS 67.2% chance of exploitation in 30 days, percentile 99.3%
public exploits
1
Exploit-DB

Summary

Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized attacker to bypass a security feature over a network.

Patch / fix

  • nuget Microsoft.AspNetCore.Server.Kestrel.Core 2.3.6
  • nuget Microsoft.AspNetCore.App.Runtime.linux-arm 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.linux-arm64 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.linux-musl-x64 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.linux-x64 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.osx-arm64 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.osx-x64 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.win-arm 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.win-arm64 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.win-x64 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • nuget Microsoft.AspNetCore.App.Runtime.win-x86 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107
  • bitnami aspnet-core 2.3.6, 8.0.21, 9.0.10
  • Microsoft ASP.NET Core 2.3 2.3.6
  • Microsoft ASP.NET Core 8.0 8.0.21
  • Microsoft ASP.NET Core 9.0 9.0.10
  • Microsoft Microsoft Visual Studio 2022 version 17.10 17.10.20
  • Microsoft Microsoft Visual Studio 2022 version 17.12 17.12.13
  • Microsoft Microsoft Visual Studio 2022 version 17.14 17.14.17
  • dotnet8 Ubuntu 22.04 LTS 8.0.121-8.0.21-0ubuntu1~22.04.1
  • dotnet8 Ubuntu 24.04 LTS 8.0.121-8.0.21-0ubuntu1~24.04.1
  • dotnet8 Ubuntu 25.10 8.0.121-8.0.21-0ubuntu1~25.10.1
  • dotnet9 Ubuntu 25.10 9.0.111-9.0.10-0ubuntu1~25.10.1
  • dotnet10 Ubuntu 24.04 LTS 10.0.100-10.0.0-0ubuntu1~24.04.1
  • dotnet10 Ubuntu 25.10 10.0.100-10.0.0~rc2-0ubuntu1~25.10.2
  • dotnet10 Ubuntu 26.04 LTS 10.0.100-10.0.0~rc2-0ubuntu1

ubuntu advisories UBUNTU-CVE-2025-55315

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • dotnet9.0 hummingbird 1 9.0.116-1.hum1
  • dotnet8.0 hummingbird 1 8.0.126-1.hum1
  • dotnet10.0 RHEL 10.1 10.0.100~rc.2.25502.107-0.12.el10_1
  • dotnet-host RHEL 10.1 10.0.0~rc.2.25502.107-0.12.el10_1
  • dotnet-sdk-10.0 RHEL 10.1 10.0.100~rc.2.25502.107-0.12.el10_1
  • dotnet-hostfxr-10.0 RHEL 10.1 10.0.0~rc.2.25502.107-0.12.el10_1
  • dotnet-runtime-10.0 RHEL 10.1 10.0.0~rc.2.25502.107-0.12.el10_1
  • dotnet-sdk-aot-10.0 RHEL 10.1 10.0.100~rc.2.25502.107-0.12.el10_1

red hat advisories RHSA-2026:9205RHSA-2026:9080RHBA-2025:20993RHBA-2025:20916RHSA-2025:18256RHSA-2025:18153

  • dotnet-sdk-8.0 AlmaLinux 8 8.0.121-1.el8_10
  • dotnet-hostfxr-8.0 AlmaLinux 8 8.0.21-1.el8_10
  • dotnet-runtime-8.0 AlmaLinux 8 8.0.21-1.el8_10
  • dotnet-sdk-dbg-8.0 AlmaLinux 8 8.0.121-1.el8_10
  • dotnet-templates-8.0 AlmaLinux 8 8.0.121-1.el8_10
  • aspnetcore-runtime-8.0 AlmaLinux 8 8.0.21-1.el8_10
  • dotnet-runtime-dbg-8.0 AlmaLinux 8 8.0.21-1.el8_10
  • dotnet-apphost-pack-8.0 AlmaLinux 8 8.0.21-1.el8_10

almalinux advisories ALSA-2025:18148ALSA-2025:18149ALSA-2025:18150ALSA-2025:18151ALSA-2025:18152ALSA-2025:18153

  • dotnet8.0 Rocky Linux 10 8.0.121-1.el10_0
  • dotnet9.0 Rocky Linux 10 9.0.111-1.el10_0
  • dotnet8.0 Rocky Linux 9 8.0.121-1.el9_6
  • dotnet9.0 Rocky Linux 9 9.0.111-1.el9_6
  • dotnet8.0 Rocky Linux 8 8.0.121-1.el8_10
  • dotnet9.0 Rocky Linux 8 9.0.111-1.el8_10

rocky linux advisories RLSA-2025:18152RLSA-2025:18153RLSA-2025:18149RLSA-2025:18151RLSA-2025:18148RLSA-2025:18150

  • dotnet8-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 8.0.21-r0
  • dotnet9-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 9.0.10-r0

alpine advisories ALPINE-CVE-2025-55315

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-2025-55315 updated cvss 8.5

dotnet: .NET Security Feature Bypass Vulnerability

  • Red Hat Enterprise Linux 9 dotnet6.0, dotnet7.0, dotnet-host, dotnet-sdk-6.0, dotnet-sdk-7.0, dotnet-hostfxr-6.0, +16 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder EUS (v.9.4) dotnet-sdk-8.0-source-built-artifacts 8.0.121-1.el9_4
    fixed: vendor fix RHSA-2025:18256
  • Red Hat Enterprise Linux AppStream (v. 8) dotnet 9.0.111-1.el8_10, dotnet8.0 8.0.121-1.el8_10, dotnet9.0 9.0.111-1.el8_10, dotnet-host 9.0.10-1.el8_10, dotnet-sdk-8.0 8.0.121-1.el8_10, dotnet-sdk-9.0 9.0.111-1.el8_10, +22 more
    fixed: vendor fix RHSA-2025:18148
  • Red Hat Enterprise Linux AppStream (v. 9) dotnet8.0 8.0.121-1.el9_6, dotnet9.0 9.0.111-1.el9_6, dotnet-host 9.0.10-1.el9_6, dotnet-sdk-8.0 8.0.121-1.el9_6, dotnet-sdk-9.0 9.0.111-1.el9_6, dotnet-hostfxr-8.0 8.0.21-1.el9_6, +35 more
    fixed: vendor fix RHSA-2025:18149
  • Red Hat Enterprise Linux AppStream (v. 10) dotnet8.0 8.0.121-1.el10_0, dotnet9.0 9.0.111-1.el10_0, dotnet-host 9.0.10-1.el10_0, dotnet-sdk-8.0 8.0.121-1.el10_0, dotnet-sdk-9.0 9.0.111-1.el10_0, dotnet-hostfxr-8.0 8.0.21-1.el10_0, +35 more
    fixed: vendor fix RHSA-2025:18152
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) dotnet8.0 8.0.121-1.el9_4, dotnet-host 8.0.21-1.el9_4, dotnet-sdk-8.0 8.0.121-1.el9_4, dotnet-hostfxr-8.0 8.0.21-1.el9_4, dotnet-runtime-8.0 8.0.21-1.el9_4, dotnet-sdk-dbg-8.0 8.0.121-1.el9_4, +8 more
    fixed: vendor fix RHSA-2025:18256
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dotnet-sdk-8.0-source-built-artifacts 8.0.121-1.el9_6, dotnet-sdk-9.0-source-built-artifacts 9.0.111-1.el9_6, dotnet-sdk-10.0-source-built-artifacts 10.0.100~rc.2.25502.107-0.10.el9_7
    fixed: vendor fix RHSA-2025:18149
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dotnet-sdk-8.0-source-built-artifacts 8.0.121-1.el10_0, dotnet-sdk-9.0-source-built-artifacts 9.0.111-1.el10_0, dotnet-sdk-10.0-source-built-artifacts 10.0.100~rc.2.25502.107-0.12.el10_1
    fixed: vendor fix RHSA-2025:18152
show 4 more
  • Red Hat Enterprise Linux CRB (v. 8) dotnet-sdk-8.0-source-built-artifacts 8.0.121-1.el8_10, dotnet-sdk-9.0-source-built-artifacts 9.0.111-1.el8_10
    fixed: vendor fix RHSA-2025:18148
  • Red Hat Hardened Images dotnet8.0 8.0.126-1.hum1, dotnet9.0 9.0.116-1.hum1
    fixed: vendor fix RHSA-2026:9080
  • Red Hat OpenShift Dev Spaces (RHOSDS) 3.25 devspaces 3.25.0-1765582207
    fixed: vendor fix RHSA-2025:23225
  • Red Hat Hardened Images dotnet10.0, dotnet-sdk-8.0 8.0.126-1.hum1, dotnet-sdk-9.0 9.0.116-1.hum1, dotnet-hostfxr-8.0 8.0.26-1.hum1, dotnet-hostfxr-9.0 9.0.15-1.hum1, dotnet-runtime-8.0 8.0.26-1.hum1, +21 more Red Hat OpenShift Dev Spaces (RHOSDS) 3.25 devspaces 3.25.0-1764891834, devspaces 3.25.0-1764892045, devspaces 3.25.0-1764892466, devspaces 3.25.0-1764892891, devspaces 3.25.0-1765225950, devspaces 3.25.0-1765246979, +9 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

Timeline

  1. Published
  2. First public exploit (EDB-52492)

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
12 mo ago

Exploit prediction

67.16% chance of exploitation in the next 30 days, higher than 99.3% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-52492 ASP.net 8.0.10 - Bypass webapps, 2026-04-06
  • gist.github.com https://gist.github.com/N3mes1s/d0897c13ca199e739ecc2b562f466040 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L/E:U/RL:O/RC:C
GitHub 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
CNA 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
OSV 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

Affected packages

ecosystem package affected fixed in
nuget Microsoft.AspNetCore.Server.Kestrel.Core
<2.3.6
2.3.6
nuget Microsoft.AspNetCore.App.Runtime.linux-arm
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.linux-arm64
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm64
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.linux-musl-x64
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.linux-x64
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.osx-arm64
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.osx-x64
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.win-arm
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.win-arm64
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.win-x64
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
nuget Microsoft.AspNetCore.App.Runtime.win-x86
>=10.0.0-rc.1.25451.107, <10.0.0-rc.2.25502.107
>=9.0.0, <9.0.10
>=8.0.0, <8.0.21
10.0.0-rc.2.25502.107
9.0.10
8.0.21
bitnami aspnet-core
>=2.3.0, <2.3.6
>=8.0.0, <8.0.21
>=9.0.0, <9.0.10
2.3.6
8.0.21
9.0.10

Affected products

  • Microsoft ASP.NET Core 2.3
  • Microsoft ASP.NET Core 8.0
  • Microsoft ASP.NET Core 9.0
  • Microsoft Microsoft Visual Studio 2022 version 17.10
  • Microsoft Microsoft Visual Studio 2022 version 17.12
  • Microsoft Microsoft Visual Studio 2022 version 17.14

Classification

Weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests

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.