ASP.NET Core WebUtilities: Denial of service due to missing resource limits
Summary
ASP.NET Core applications that use the NuGet package Microsoft.AspNetCore.WebUtilities in affected 2.3 versions allocate resources without limits or throttling. A remote, unauthenticated attacker can exhaust these resources and make the application unavailable. No user interaction is required. Exposure is highest for legacy applications that are reachable from the internet.
Affected
- Microsoft.AspNetCore.WebUtilities 2.3.x before 2.3.14. The CVE record gives 2.3.12 to below 2.3.14, while the vendor advisory mirror gives 2.3.0 to 2.3.13. Verify the exact range on the MSRC page.
- Unknown: whether the .NET 8.0 to 11.0 runtime packages are affected, because the captured advisory text shows no affected rows for them.
Fixed in
- Microsoft.AspNetCore.WebUtilities 2.3.14 or later, according to the Microsoft advisory mirror.
Workaround
Unknown. No workaround is documented in the sources. Updating to 2.3.14 is the only documented fix.
Exploitation
- Not known to be exploited as of 11 Nov 2026 (OffSeq). Not listed as KEV (Strix).
- CISA SSVC: exploitation none, automatable yes, technical impact partial.
- No public proof of concept found. This means nothing was found, not that none exists.
Our recommendation
- Inventory .NET projects for Microsoft.AspNetCore.WebUtilities 2.3.x, including transitive references pulled in through Microsoft.AspNetCore.Http.
- Update to version 2.3.14 or later, then rebuild and redeploy the applications.
- Prioritise internet-facing legacy applications.
- Monitor for unusual resource consumption and availability problems.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide (MSRC) msrc.microsoft.com
- GitHub advisory mirror (dotnet/announcements #512) github.com
- November 2026 ASP.NET Core roundup (dotnet/announcements #504) github.com
- OffSeq threat radar entry radar.offseq.com
- Strix CVE record www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 05:34.
Original description (NVD)
Allocation of resources without limits or throttling in ASP.NET Core allows an unauthorized attacker to deny service over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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