CVE-2025-55315
CriticalPublic exploitMicrosoft Security Advisory CVE-2025-55315: .NET Security Feature Bypass Vulnerability
Published Oct 15, 2025 · Updated Sep 10, 2026 · Also known as BIT-aspnet-core-2025-55315, GHSA-5rrx-jjjq-q2r5, UBUNTU-CVE-2025-55315
Key Facts
Patch immediately- CVE-2025-55315 is a critical-severity vulnerability (CVSS 9.9 v3.1) affecting Asp.net Core (Microsoft), Visual Studio 2022 (Microsoft), dotnet8-runtime (alpine) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 66% probability of exploitation in the next 30 days.
- Fixed versions are available, including ASP.NET Core 2.3 2.3.6, ASP.NET Core 8.0 8.0.21, ASP.NET Core 9.0 9.0.10.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
9.9
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
EPSS (30-day exploit likelihood)
66%
Higher than 99.2% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2025-55315 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Affected Products
303 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Asp.net CoreMicrosoft | See advisory | 2.3.6 |
| Visual Studio 2022Microsoft | See advisory | 17.10.20 |
| dotnet8-runtimealpine | See advisory | 8.0.21-r0 |
| dotnet9-runtimealpine | See advisory | 9.0.10-r0 |
| azure-functions-extension-bundles-4chainguard | See advisory | 4.28.0-r1 |
Patched Releases
ASP.NET Core 2.3
2.3.6
ASP.NET Core 8.0
8.0.21
ASP.NET Core 9.0
9.0.10
aspnet-core
2.3.6, 8.0.21, 9.0.10
aspnetcore-runtime-10.0
10.0.0~rc.2.25502.107-0.12.0.1.el10_1, 10.0.0~rc2-0ubuntu1~25.10.2
aspnetcore-runtime-8.0
8.0.21-0ubuntu1~22.04.1, 8.0.21-0ubuntu1~24.04.1, 8.0.21-0ubuntu1~25.04.1, 8.0.21-0ubuntu1~25.10.1, 8.0.21-1.0.1.el10_0, 8.0.21-1.0.1.el8_10, 8.0.21-1.0.1.el9_6, 8.0.21-1.amzn2023.0.1
aspnetcore-runtime-9.0
9.0.10-0ubuntu1~25.04.1, 9.0.10-0ubuntu1~25.10.1, 9.0.10-1.0.1.el10_0, 9.0.10-1.0.1.el8_10, 9.0.10-1.0.1.el9_6, 9.0.10-1.amzn2023.0.1
aspnetcore-runtime-dbg-10.0
10.0.0~rc.2.25502.107-0.12.0.1.el10_1, 10.0.0~rc2-0ubuntu1~25.10.2
aspnetcore-runtime-dbg-8.0
8.0.21-0ubuntu1~22.04.1, 8.0.21-0ubuntu1~24.04.1, 8.0.21-0ubuntu1~25.04.1, 8.0.21-0ubuntu1~25.10.1, 8.0.21-1.0.1.el10_0, 8.0.21-1.0.1.el8_10, 8.0.21-1.0.1.el9_6, 8.0.21-1.amzn2023.0.1
aspnetcore-runtime-dbg-9.0
9.0.10-0ubuntu1~25.04.1, 9.0.10-0ubuntu1~25.10.1, 9.0.10-1.0.1.el10_0, 9.0.10-1.0.1.el8_10, 9.0.10-1.0.1.el9_6, 9.0.10-1.amzn2023.0.1
aspnetcore-targeting-pack-10.0
10.0.0~rc.2.25502.107-0.12.0.1.el10_1, 10.0.0~rc2-0ubuntu1~25.10.2
aspnetcore-targeting-pack-8.0
8.0.21-0ubuntu1~22.04.1, 8.0.21-0ubuntu1~24.04.1, 8.0.21-0ubuntu1~25.04.1, 8.0.21-0ubuntu1~25.10.1, 8.0.21-1.0.1.el10_0, 8.0.21-1.0.1.el8_10, 8.0.21-1.0.1.el9_6, 8.0.21-1.amzn2023.0.1
aspnetcore-targeting-pack-9.0
9.0.10-0ubuntu1~25.04.1, 9.0.10-0ubuntu1~25.10.1, 9.0.10-1.0.1.el10_0, 9.0.10-1.0.1.el8_10, 9.0.10-1.0.1.el9_6, 9.0.10-1.amzn2023.0.1
azure-functions-extension-bundles-4
4.28.0-r1
devspaces/udi-rhel9:3.25.0
1765582207
dotnet
8.0.121-1.amzn2023.0.1, 9.0.111-1.0.1.el8_10, 9.0.111-1.amzn2023.0.1
dotnet-8
8.0.121-r0
dotnet-9
9.0.111-r0
dotnet-apphost-pack-10.0
10.0.0~rc.2.25502.107-0.12.0.1.el10_1, 10.0.0~rc2-0ubuntu1~25.10.2
dotnet-apphost-pack-8.0
8.0.21-0ubuntu1~22.04.1, 8.0.21-0ubuntu1~24.04.1, 8.0.21-0ubuntu1~25.04.1, 8.0.21-0ubuntu1~25.10.1, 8.0.21-1.0.1.el10_0, 8.0.21-1.0.1.el8_10, 8.0.21-1.0.1.el9_6, 8.0.21-1.amzn2023.0.1
dotnet-apphost-pack-9.0
9.0.10-0ubuntu1~25.04.1, 9.0.10-0ubuntu1~25.10.1, 9.0.10-1.0.1.el10_0, 9.0.10-1.0.1.el8_10, 9.0.10-1.0.1.el9_6, 9.0.10-1.amzn2023.0.1
dotnet-bootstrap-8
8.0.122-r0
dotnet-bootstrap-9
9.0.112-r0
dotnet-host
10.0.0~rc.2.25502.107-0.12.0.1.el10_1, 8.0.21-1.amzn2023.0.1, 9.0.10-1.0.1.el10_0, 9.0.10-1.0.1.el8_10, 9.0.10-1.0.1.el9_6, 9.0.10-1.amzn2023.0.1
dotnet-host-10.0
10.0.0~rc2-0ubuntu1~25.10.2
Timeline
Publicly disclosed
Oct 15, 2025
Last updated
Sep 10, 2026
Weakness Type
- CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
References
- advisoryRHBA-2025:20916
- advisoryRHBA-2025:20993
- advisoryRHSA-2025:18148
- advisoryRHSA-2025:18149
- advisoryRHSA-2025:18150
FAQ
Common Questions.
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.
Affected: Asp.net Core (Microsoft); Visual Studio 2022 (Microsoft); dotnet8-runtime (alpine), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including ASP.NET Core 2.3 2.3.6, ASP.NET Core 8.0 8.0.21, ASP.NET Core 9.0 9.0.10.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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