Allocation of Resources Without Limits or Throttling Affecting microsoft.aspnetcore.webutilities package, versions [8.0.0-preview.1.23112.2,8.0.34)[9.0.0-preview.1.24081.5,9.0.23)[10.0.0-preview.1.25120.3,10.0.15)[11.0.0-preview.1.26104.118,11.0.0)
Threat Intelligence
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.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about Allocation of Resources Without Limits or Throttling vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-DOTNET-MICROSOFTASPNETCOREWEBUTILITIES-22409070
- published11 Nov 2026
- disclosed9 Nov 2026
- creditn0irx
Introduced: 9 Nov 2026
NewCVE-2026-114149 (opens in a new tab)How to fix?
Upgrade Microsoft.AspNetCore.WebUtilities to version 8.0.34, 9.0.23, 10.0.15, 11.0.0 or higher.
Overview
Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling in the MultipartReader.ReadHeadersAsync method, which enforces the multipart HeadersCountLimit against the accumulator's distinct-key count rather than its total value count. An attacker can bypass the configured header-count limit and drive excessive memory and CPU use by sending a multipart section that repeats a single header name many times, since the duplicate values collapse to one key and never trip the limit. Reaching this requires an endpoint that reads multipart or form request bodies through ReadFormAsync, MVC or Minimal-API form and file binding, or MultipartReader directly.