CVE-2025-26646

highpriority · track · 0EPSS 0.013 · 70 %ileDEEUNLRUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
1.27% (70th) EPSS
CVSS 8 · high
Is it mine?
87 products
Check your exposure
Who says so?
7 sources
cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

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.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

8.0
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.18highAV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.18highCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · ENISA EU
v3.18highCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:Hsecondary · secure@microsoft.com USexploitability 2.1 · impact 5.9
v3.18highCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:Hsecondary · OSV
v3.17.3highCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.18highCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · Microsoft Security Response Center US
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

05

affected products (87)

Products and version ranges known to be affected.

showing 20 of 87
06

advisories (6)

Vendor and ecosystem advisories describing this.

  • NCSC-2025-0153Kwetsbaarheden verholpen in Microsoft Developer ToolsNL2025-05-13csaf · ncsc_nlNL

    Microsoft heeft kwetsbaarheden verholpen in diverse Developer Tools.

  • WID-SEC-W-2025-1015Microsoft Developer Tools: Mehrere SchwachstellenDeutsch2025-05-13csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Microsoft Visual Studio, Microsoft Visual Studio Code, Microsoft Azure DevOps und Microsoft .NET Framework ausnutzen, um seine Privilegien zu eskalieren, Informationen offenzulegen, Sicherheitsmaßnahmen zu umgehen, beliebigen Programmcode auszuführen oder Daten zu manipulieren.

  • msrc_CVE-2025-26646.NET, Visual Studio, and Build Tools for Visual Studio Spoofing Vulnerability2025-05-13csaf · msrc_csafUS

    To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

  • GHSA-h4j7-5rxr-p4wcMicrosoft.Build.Tasks.Core .NET Spoofing Vulnerability2025-05-13ghsa · osvUS

    # Microsoft Security Advisory CVE-2025-26646: .NET Spoofing Vulnerability ## <a name="executive-summary"></a>Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 9.0.xxx and .NET 8.0.xxx SDK. This advisory also provides guidance on what developers can do to update their applications to address this vulnerability. A vulnerability exists in .NET SDK or MSBuild applications where external control of file name or path allows an unauthorized attacked to perform spoofing over a network. ## Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/356 ### <a name="mitigation-factors"></a>Mitigation factors Projects which do not utilize the [DownloadFile](https://learn.microsoft.com/visualstudio/msbuild/downloadfile-task) build task are not susceptible to this vulnerability. ## <a name="affected-software"></a>Affected software * Any installation of .NET 9.0.105 SDK, .NET 9.0.203 SDK or earlier. * Any installation of .NET 8.0.115 SDK, .NET 8.0.311 or .NET 8.0.312 SDK, .NET 8.0.408 or .NET 8.0.409 SDK or earlier. ## <a name="affected-packages"></a>Affected Packages The vulnerability affects any Microsoft .NET Core project if it uses any of affected packages versions listed below Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- [Microsoft.Build.Tasks.Core](https://www.nuget.org/packages/Microsoft.Build.Tasks.Core) |>= 15.8.166, <=15.9.20<br />>=16.0.461, <= 16.11.0<br />>= 17.0.0, <= 17.8.3<br/>>= 17.9.5, <= 17.10.4<br />17.11.4<br />17.12.6 <br />17.13.9 | 15.9.30<br />16.11.6<br />17.8.29<br/>17.10.29<br />17.12.36<br />17.13.26 <br />17.14.8 ## Advisory FAQ ### <a name="how-affected"></a>How do I know if I am affected? If you have a .NET SDK with a version listed, or an affected package listed in [affected software](#affected-packages) or [affected packages](#affected-software), you're exposed to the vulnerability. ### <a name="how-fix"></a>How do I fix the issue? 1. To fix the issue please install the latest version of .NET 9.0 SDK or .NET 8.0 SDK. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs. 2. If your application references the vulnerable package, update the package reference to the patched version. * You can list the versions you have installed by running the `dotnet --info` command. You will see output like the following; ``` .NET SDK: Version: 9.0.100 Commit: 59db016f11 Workload version: 9.0.100-manifests.3068a692 MSBuild version: 17.12.7+5b8665660 Runtime Environment: OS Name: Mac OS X OS Version: 15.2 OS Platform: Darwin RID: osx-arm64 Base Path: /usr/local/share/dotnet/sdk/9.0.100/ .NET workloads installed: There are no installed workloads to display. Configured to use loose manifests when installing new manifests. Host: Version: 9.0.0 Architecture: arm64 Commit: 9d5a6a9aa4 .NET SDKs installed: 9.0.100 [/usr/local/share/dotnet/sdk] .NET runtimes installed: Microsoft.AspNetCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.NETCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App] Other architectures found: x64 [/usr/local/share/dotnet] registered at [/etc/dotnet/install_location_x64] Environment variables: Not set global.json file: Not found Learn more: https://aka.ms/dotnet/info Download .NET: https://aka.ms/dotnet/download ``` * If you're using .NET 9.0, you should download and install the appropriate SDK: `.NET 9.0.300` for Visual Studio 2022 v17.14, `.NET 9.0.204` for v17.13, or `.NET 9.0.106` for v17.12. Download from https://dotnet.microsoft.com/download/dotnet-core/9.0. * If you're using .NET 8.0, you should download and install the appropriate SDK: `.NET 8.0.410` for Visual Studio 2022 v17.11, `.NET 8.0.313` for v17.10, or `.NET 8.0.116` for v17.8. Download from https://dotnet.microsoft.com/download/dotnet-core/8.0. Once you have installed the updated SDK, restart your apps for the update to take effect. ## Other Information ### Reporting Security Issues If you have found a potential security issue in .NET 8.0 or .NET 9.0, please email details to secure@microsoft.com. Reports may qualify for the Microsoft .NET Core & .NET 5 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/aspnetcore. 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.

  • BIT-dotnet-2025-26646.NET, Visual Studio, and Build Tools for Visual Studio Spoofing Vulnerability2025-07-11vendor · osvUS

    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.

  • BIT-dotnet-sdk-2025-26646.NET, Visual Studio, and Build Tools for Visual Studio Spoofing Vulnerability2025-07-11vendor · osvUS

    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.

07

also known as (7)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

09

references (4)

External citations — patches, advisories, analysis.

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