ASP.NET Core Elevation of Privilege Vulnerability

Check whether my systems are affected by CVE-2026-109481 (ASP.NET Core Elevation of Privilege Vulnerability), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-109481 (entry last updated 2026-11-10):
Affected:
- Microsoft .NET 11.0 installed on Linux: from 11.0.0-preview.1, fixed in 11.0.0
- Microsoft .NET 11.0 installed on Mac OS: from 11.0.0-preview.1, fixed in 11.0.0
- Microsoft .NET 11.0 installed on Windows: from 11.0.0-preview.1, fixed in 11.0.0
- Microsoft Microsoft Visual Studio 2026 version 18.12: from 18.12.0, fixed in 18.12.0
- NuGet package Microsoft.AspNetCore.App.Runtime.linux-arm: from 11.0.0-preview.6.26359.118, fixed in 11.0.0
- NuGet package Microsoft.AspNetCore.App.Runtime.linux-arm64: from 11.0.0-preview.6.26359.118, fixed in 11.0.0
- NuGet package Microsoft.AspNetCore.App.Runtime.linux-musl-arm: from 11.0.0-preview.6.26359.118, fixed in 11.0.0
- NuGet package Microsoft.AspNetCore.App.Runtime.linux-musl-arm64: from 11.0.0-preview.6.26359.118, fixed in 11.0.0
- NuGet package Microsoft.AspNetCore.App.Runtime.linux-musl-x64: from 11.0.0-preview.6.26359.118, fixed in 11.0.0
- NuGet package Microsoft.AspNetCore.App.Runtime.linux-x64: from 11.0.0-preview.6.26359.118, fixed in 11.0.0
- and 5 more affected products, listed on https://cve.now/CVE-2026-109481
Fixed versions: 11.0.0, 18.12.0.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-109481 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-109481 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Packages (NuGet): find every lockfile in each project and run check_stack from the cve.now MCP server on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109481
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-109481
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-109481.