# CVE-2025-26646: .NET, Visual Studio, and Build Tools for Visual Studio Spoofing Vulnerability > An authorized attacker can exploit external control of file names or paths in .NET and Visual Studio to perform spoofing over a network. - **Severity:** High 8.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 13 May 2025 - **Updated:** 26 Feb 2026 - **Also known as:** ALSA-2025:7571, ALSA-2025:7589, ALSA-2025:7598, ALSA-2025:7599, ALSA-2025:7600, ALSA-2025:7601, BELL-CVE-2025-26646, BIT-dotnet-2025-26646, BIT-dotnet-sdk-2025-26646, ECHO-8c58-e4fe-da70, GHSA-h4j7-5rxr-p4wc, MINI-8gfx-2v79-jf76, MINI-ff6h-x49j-cj7j, MINI-g75w-2h99-vww9, RHSA-2025:7571, RHSA-2025:7589, RHSA-2025:7598, RHSA-2025:7599, RHSA-2025:7600, RHSA-2025:7601, RHSA-2025:7603, RLSA-2025:7571, RLSA-2025:7589, RLSA-2025:7598, RLSA-2025:7599, RLSA-2025:7601, ROOT-APP-NUGET-CVE-2025-26646, UBUNTU-CVE-2025-26646, USN-7509-1 ## What is CVE-2025-26646? CVE-2025-26646 is a high-severity path traversal vulnerability in Microsoft .Net, published on 13 May 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link. ### Official description External control of file name or path in .NET, Visual Studio, and Build Tools for Visual Studio allows an authorized attacker to perform spoofing over a network. Weakness: CWE-73 (External Control of File Name or Path) ## Which versions are affected by CVE-2025-26646? 16 open source packages ship an affected version, including Microsoft.Build.Tasks.Core, dotnet and dotnet-sdk. It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `Microsoft.Build.Tasks.Core` | NuGet | From 15.8.166 | 15.9.30 | | `Microsoft.Build.Tasks.Core` | NuGet | From 15.8.166 | 15.9.30 | | `Microsoft.Build.Tasks.Core` | NuGet | From 16.0.461 | 16.11.6 | | `Microsoft.Build.Tasks.Core` | NuGet | From 16.0.461 | 16.11.6 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.0.0 | 17.8.29 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.0.0 | 17.8.29 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.11.4 | 17.12.36 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.11.4 | 17.12.36 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.12.6 | 17.13.26 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.12.6 | 17.13.26 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.13.9 | 17.14.8 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.13.9 | 17.14.8 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.9.5 | 17.10.29 | | `Microsoft.Build.Tasks.Core` | NuGet | From 17.9.5 | 17.10.29 | | `dotnet` | Bitnami | From 8.0.0 | 8.0.16, 9.0.5 | | `dotnet-sdk` | Bitnami | From 8.0.0 | 8.0.101, 9.0.100 | | `aspnetcore-runtime-8.0` | AlmaLinux:10 | All versions | 8.0.16-1.el10_0 | | `aspnetcore-runtime-9.0` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | | `aspnetcore-runtime-dbg-8.0` | AlmaLinux:10 | All versions | 8.0.16-1.el10_0 | | `aspnetcore-runtime-dbg-9.0` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | | `aspnetcore-targeting-pack-8.0` | AlmaLinux:10 | All versions | 8.0.16-1.el10_0 | | `aspnetcore-targeting-pack-9.0` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | | `dotnet-apphost-pack-8.0` | AlmaLinux:10 | All versions | 8.0.16-1.el10_0 | | `dotnet-apphost-pack-9.0` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | | `dotnet-host` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | | `dotnet-hostfxr-8.0` | AlmaLinux:10 | All versions | 8.0.16-1.el10_0 | | `dotnet-hostfxr-9.0` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | | `dotnet-runtime-8.0` | AlmaLinux:10 | All versions | 8.0.16-1.el10_0 | | `dotnet-runtime-9.0` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | | `dotnet-runtime-dbg-8.0` | AlmaLinux:10 | All versions | 8.0.16-1.el10_0 | | `dotnet-runtime-dbg-9.0` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | | `dotnet-sdk-8.0` | AlmaLinux:10 | All versions | 8.0.116-1.el10_0 | | `dotnet-sdk-8.0-source-built-artifacts` | AlmaLinux:10 | All versions | 8.0.116-1.el10_0 | | `dotnet-sdk-9.0` | AlmaLinux:10 | All versions | 9.0.106-1.el10_0 | | `dotnet-sdk-9.0-source-built-artifacts` | AlmaLinux:10 | All versions | 9.0.106-1.el10_0 | | `dotnet-sdk-aot-9.0` | AlmaLinux:10 | All versions | 9.0.106-1.el10_0 | | `dotnet-sdk-dbg-8.0` | AlmaLinux:10 | All versions | 8.0.116-1.el10_0 | | `dotnet-sdk-dbg-9.0` | AlmaLinux:10 | All versions | 9.0.106-1.el10_0 | | `dotnet-targeting-pack-8.0` | AlmaLinux:10 | All versions | 8.0.16-1.el10_0 | | `dotnet-targeting-pack-9.0` | AlmaLinux:10 | All versions | 9.0.5-1.el10_0 | Products: Microsoft .Net, Microsoft Build Tools, Microsoft Visual Studio 2022. ## How do I fix CVE-2025-26646? Upgrade Microsoft.Build.Tasks.Core to a fixed version for your release line: 15.9.30, 16.11.6, 17.8.29 or 17.12.36. ## Is CVE-2025-26646 being exploited? There is no known exploitation of CVE-2025-26646 in the wild and no public exploit code. ## Other vulnerabilities in Microsoft .Net - [CVE-2024-43498](https://insights.sbomify.com/CVE-2024-43498/): .NET and Visual Studio Remote Code Execution Vulnerability (critical 9.8) - [CVE-2024-0057](https://insights.sbomify.com/CVE-2024-0057/): NET, .NET Framework, and Visual Studio Security Feature Bypass Vulnerability (critical 9.1) - [CVE-2026-96957](https://insights.sbomify.com/CVE-2026-96957/): .NET Security Feature Bypass Vulnerability (high 8.8) - [CVE-2026-69439](https://insights.sbomify.com/CVE-2026-69439/): .NET and Visual Studio Elevation of Privilege Vulnerability (high 8.8) - [CVE-2026-71328](https://insights.sbomify.com/CVE-2026-71328/): .NET and Visual Studio Remote Code Execution Vulnerability (high 8.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-26646 and fix it if it is affected. What it is: CVE-2025-26646 is a high-severity path traversal vulnerability in Microsoft .Net, published on 13 May 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2025-26646 in the wild and no public exploit code. Affected packages and fixed versions: - Microsoft.Build.Tasks.Core (NuGet): affected from 15.8.166; fixed in 15.9.30 - Microsoft.Build.Tasks.Core (NuGet): affected from 15.8.166; fixed in 15.9.30 - Microsoft.Build.Tasks.Core (NuGet): affected from 16.0.461; fixed in 16.11.6 - Microsoft.Build.Tasks.Core (NuGet): affected from 16.0.461; fixed in 16.11.6 - Microsoft.Build.Tasks.Core (NuGet): affected from 17.0.0; fixed in 17.8.29 - Microsoft.Build.Tasks.Core (NuGet): affected from 17.0.0; fixed in 17.8.29 - Microsoft.Build.Tasks.Core (NuGet): affected from 17.11.4; fixed in 17.12.36 - Microsoft.Build.Tasks.Core (NuGet): affected from 17.11.4; fixed in 17.12.36 - Microsoft.Build.Tasks.Core (NuGet): affected from 17.12.6; fixed in 17.13.26 - Microsoft.Build.Tasks.Core (NuGet): affected from 17.12.6; fixed in 17.13.26 - Microsoft.Build.Tasks.Core (NuGet): affected from 17.13.9; fixed in 17.14.8 - Microsoft.Build.Tasks.Core (NuGet): affected from 17.13.9; fixed in 17.14.8 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-26646/ (Markdown: https://insights.sbomify.com/CVE-2025-26646/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-26646 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-26646 - OSV: https://osv.dev/vulnerability/CVE-2025-26646 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-26646/ Summaries are generated and may contain mistakes; the official description above is the record.