Microsoft.AspNetCore.WebUtilities: Microsoft Security Advisory CVE-2026-118750 - ASP.NET Core Denial of Service
Affects Microsoft.AspNetCore.WebUtilitiesSource GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade to 2.3.14 soon.
Data as of 11 Nov 2026, 00:23 UTC
Thin evidence
One scorer or none| CNA (microsoft) | CVSS 3.1 | 7.5 |
|---|
- Patch
- Available – fixed in 2.3.14
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade Microsoft.AspNetCore.WebUtilities to 2.3.14.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| NuGetMicrosoft.AspNetCore.WebUtilities | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Update the Microsoft.AspNetCore.WebUtilities package to version 2.3.14 or later. Applications referencing Microsoft.AspNetCore.Http should ensure that Microsoft.AspNetCore.WebUtilities resolves to version 2.3.14 or newer, including transitive dependencies. Rebuild and redeploy applications after updating the package references. Updating only the runtime is insufficient; the standalone package references must be updated.
Description
A denial of service vulnerability exists in Microsoft.AspNetCore.WebUtilities versions 2.3.0 through 2.3.13. The issue arises from the FileBufferingReadStream buffer allocation, which can allow unauthenticated multipart-form requests to exhaust memory. This vulnerability has a CVSS 3.1 base score of 7.5 (high severity). A fixed version 2.3.14 is available to address this issue.
References
- github.com/dotnet/aspnetcore/security/advisories/GHSA-6527-9fp8-r4x6 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-118750 (opens in a new tab)
- github.com/dotnet/announcements/issues/512 (opens in a new tab)
- github.com/dotnet/aspnetcore/commit/9a26c7414a4fbff45535c0830253c1b4479b0073 (opens in a new tab)
- github.com/dotnet/aspnetcore (opens in a new tab)
- github.com/dotnet/aspnetcore/discussions/70476 (opens in a new tab)
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-118750 (opens in a new tab)