CVE-2025-55247 — Microsoft.Build.Tasks.Core
HIGHCVE-2025-55247 is a high-severity (CVSS 7.3) CWE-59 vulnerability in Microsoft.Build.Tasks.Core. A fix is available for Microsoft.Build.Tasks.Core — see the affected versions and patch details below.
Microsoft Security Advisory CVE-2025-55247 | .NET Denial of Service Vulnerability
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-55247.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2025-55247 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
Microsoft.Build.Tasks.Core.NETMicrosoft.Build.Tasks.Core.NETMicrosoft.Build.Tasks.Core.NETMicrosoft.Build.Tasks.Core.NETMicrosoft.Build.Tasks.Core.NETMicrosoft.Build.Tasks.Core.NETMicrosoft.Build.NETMicrosoft.Build+10 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
Improper link resolution before file access ('link following') in .NET allows an authorized attacker to elevate privileges locally.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.Build.Tasks.Core | ≥ 17.15.0-preview-25277-114&&< 18.0.0-preview-25476-107 | 18.0.0-preview-25476-107dotnet add package Microsoft.Build.Tasks.Core --version 18.0.0-preview-25476-107 |
| .NETNuGet | Microsoft.Build.Tasks.Core | ≥ 17.14.0&&< 17.14.28 | 17.14.28dotnet add package Microsoft.Build.Tasks.Core --version 17.14.28 |
| .NETNuGet | Microsoft.Build.Tasks.Core | ≥ 17.12.0&&< 17.12.50 | 17.12.50dotnet add package Microsoft.Build.Tasks.Core --version 17.12.50 |
| .NETNuGet | Microsoft.Build.Tasks.Core | ≥ 17.11.0&&< 17.11.48 | 17.11.48dotnet add package Microsoft.Build.Tasks.Core --version 17.11.48 |
| .NETNuGet | Microsoft.Build.Tasks.Core | ≥ 17.10.0&&< 17.10.46 | 17.10.46dotnet add package Microsoft.Build.Tasks.Core --version 17.10.46 |
| .NETNuGet | Microsoft.Build.Tasks.Core | ≥ 17.8.0&&< 17.8.43 | 17.8.43dotnet add package Microsoft.Build.Tasks.Core --version 17.8.43 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.Build.Tasks.Core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.Build.Tasks.Core to 18.0.0-preview-25476-107 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-55247 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-55247 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-55247. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
The Red Hat Product Security team has assessed this issue as Moderate. Predictable MSBuild temporary directory paths on Linux allow a local user to precreate or manipulate build temp directories, causing build failures (denial of service) on shared build hosts or CI runners using the affected .NET packages. ``` .NET…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | dotnet8.0-0:8.0.121-1.el10_0 | RHSA-2025:18152 |
| Red Hat Enterprise Linux 10 | dotnet9.0-0:9.0.111-1.el10_0 | RHSA-2025:18153 |
| Red Hat Enterprise Linux 10 | dotnet10.0-0:10.0.100~rc.2.25502.107-0.12.el10_1 | RHBA-2025:20993 |
| Red Hat Enterprise Linux 8 | dotnet8.0-0:8.0.121-1.el8_10 | RHSA-2025:18148 |
| Red Hat Enterprise Linux 8 | dotnet9.0-0:9.0.111-1.el8_10 | RHSA-2025:18150 |
| Red Hat Enterprise Linux 9 | dotnet10.0-0:10.0.100~rc.2.25502.107-0.10.el9_7 | RHBA-2025:20916 |
| Red Hat Enterprise Linux 9 | dotnet8.0-0:8.0.121-1.el9_6 | RHSA-2025:18149 |
| Red Hat Enterprise Linux 9 | dotnet9.0-0:9.0.111-1.el9_6 | RHSA-2025:18151 |
Frequently Asked Questions
Is CVE-2025-55247 in your dependencies?
O3 Security finds CVE-2025-55247 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.