HTTP Request Smuggling Affecting microsoft.aspnetcore.server.kestrel.core package, versions [,2.3.6)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DOTNET-MICROSOFTASPNETCORESERVERKESTRELCORE-13551956
- published15 Oct 2025
- disclosed14 Oct 2025
- creditSid
Introduced: 14 Oct 2025
CVE-2025-55315 (opens in a new tab)How to fix?
Upgrade Microsoft.AspNetCore.Server.Kestrel.Core to version 2.3.6 or higher.
Overview
Microsoft.AspNetCore.Server.Kestrel.Core is a core components of ASP.NET Core Kestrel cross-platform web server.
Affected versions of this package are vulnerable to HTTP Request Smuggling via the interpretation of chunked HTTP requests. An attacker can bypass security restrictions and potentially access or manipulate sensitive data by sending specially crafted HTTP requests that exploit inconsistencies in request parsing.