GHSA-6527-9FP8-R4X6
Vulnerability from github – Published: 2026-11-10 23:32 – Updated: 2026-11-10 23:32Executive summary
Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core. This advisory provides guidance on updating affected applications and components.
FileBufferingReadStream buffer allocation can allow unauthenticated multipart-form requests to exhaust memory.
Announcement
Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/512
CVSS Details
- Version: 3.1
- Severity: High
- Score: 7.5 (base score)
- Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C - Weakness: CWE-770
Affected Platforms
- Platforms: Any supported OS
- Architectures: All
Affected Packages
The table lists the affected package range and the fixed NuGet version.
ASP.NET Core 2.3 - standalone packages
| Package | Affected version | Patched version |
|---|---|---|
| Microsoft.AspNetCore.WebUtilities | >= 2.3.0, <= 2.3.13 | 2.3.14 |
Advisory FAQ
How do I know if I am affected?
Check the application's Microsoft.AspNetCore.WebUtilities package reference against the affected range above, including transitive dependencies brought in by Microsoft.AspNetCore.Http. Use dotnet list <PROJECT> package --include-transitive to inspect resolved dependencies.
How do I fix the issue?
Update each applicable package reference to its patched version listed above, then rebuild and redeploy the application. Updating only the installed runtime does not update an application's standalone package references.
Applications referencing Microsoft.AspNetCore.Http must resolve Microsoft.AspNetCore.WebUtilities to version 2.3.14 or later. Add or update a direct WebUtilities reference if necessary to override an older transitive dependency.
Other Information
Reporting Security Issues
If you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ.
Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.
Support
You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.
Disclaimer
The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
External Links
Acknowledgements
- NavSec4
Revisions
V1.0 (November 10, 2026): Advisory published.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 2.3.13"
},
"package": {
"ecosystem": "NuGet",
"name": "Microsoft.AspNetCore.WebUtilities"
},
"ranges": [
{
"events": [
{
"introduced": "2.3.0"
},
{
"fixed": "2.3.14"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-118750"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-11-10T23:32:00Z",
"nvd_published_at": "2026-11-10T19:19:51Z",
"severity": "MODERATE"
},
"details": "## Executive summary\n\nMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core. This advisory provides guidance on updating affected applications and components.\n\nFileBufferingReadStream buffer allocation can allow unauthenticated multipart-form requests to exhaust memory.\n\n## Announcement\n\nAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/512\n\n## CVSS Details\n\n- **Version:** 3.1\n- **Severity:** High\n- **Score:** 7.5 (base score)\n- **Vector:** `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C`\n- **Weakness:** CWE-770\n\n## Affected Platforms\n\n- **Platforms:** Any supported OS\n- **Architectures:** All\n\n## \u003ca name=\"affected-packages\"\u003e\u003c/a\u003eAffected Packages\n\nThe table lists the affected package range and the fixed NuGet version.\n\n### ASP.NET Core 2.3 - standalone packages\n\nPackage | Affected version | Patched version\n--- | --- | ---\n[Microsoft.AspNetCore.WebUtilities](https://www.nuget.org/packages/Microsoft.AspNetCore.WebUtilities) | \u003e= 2.3.0, \u003c= 2.3.13 | 2.3.14\n\n## Advisory FAQ\n\n### \u003ca name=\"how-affected\"\u003e\u003c/a\u003eHow do I know if I am affected?\n\nCheck the application\u0027s Microsoft.AspNetCore.WebUtilities package reference against the affected range above, including transitive dependencies brought in by Microsoft.AspNetCore.Http. Use `dotnet list \u003cPROJECT\u003e package --include-transitive` to inspect resolved dependencies.\n\n### \u003ca name=\"how-fix\"\u003e\u003c/a\u003eHow do I fix the issue?\n\nUpdate each applicable package reference to its patched version listed above, then rebuild and redeploy the application. Updating only the installed runtime does not update an application\u0027s standalone package references.\n\nApplications referencing Microsoft.AspNetCore.Http must resolve Microsoft.AspNetCore.WebUtilities to version 2.3.14 or later. Add or update a direct WebUtilities reference if necessary to override an older transitive dependency.\n\n## Other Information\n\n### Reporting Security Issues\n\nIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). Further information can be found in the MSRC [Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue).\n\nSecurity reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.\n\n### Support\n\nYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.\n\n### Disclaimer\n\nThe information provided in this advisory is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.\n\n### External Links\n\n[CVE-2026-118750](https://www.cve.org/CVERecord?id=CVE-2026-118750)\n\n### Acknowledgements\n\n- NavSec4\n\n### Revisions\n\nV1.0 (November 10, 2026): Advisory published.",
"id": "GHSA-6527-9fp8-r4x6",
"modified": "2026-11-10T23:32:00Z",
"published": "2026-11-10T23:32:00Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/dotnet/aspnetcore/security/advisories/GHSA-6527-9fp8-r4x6"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118750"
},
{
"type": "WEB",
"url": "https://github.com/dotnet/announcements/issues/512"
},
{
"type": "WEB",
"url": "https://github.com/dotnet/aspnetcore/commit/9a26c7414a4fbff45535c0830253c1b4479b0073"
},
{
"type": "PACKAGE",
"url": "https://github.com/dotnet/aspnetcore"
},
{
"type": "WEB",
"url": "https://github.com/dotnet/aspnetcore/discussions/70476"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-118750"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C",
"type": "CVSS_V3"
}
],
"summary": "Microsoft Security Advisory CVE-2026-118750 - ASP.NET Core Denial of Service Vulnerability"
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.