CVE-2025-55240 Overview
CVE-2025-55240 is an improper access control vulnerability in Microsoft Visual Studio. An authorized local attacker can exploit the flaw to elevate privileges on an affected system. The issue is tracked under CWE-284: Improper Access Control and affects Visual Studio 2017, 2019, and 2022.
Microsoft published the advisory on October 14, 2025. Successful exploitation requires local access, low privileges, and user interaction, but yields high confidentiality, integrity, and availability impact within the affected component.
Critical Impact
A local authenticated user can leverage misconfigured access controls in Visual Studio to gain elevated privileges, enabling execution of code or modification of resources beyond their authorization boundary.
Affected Products
- Microsoft Visual Studio 2017
- Microsoft Visual Studio 2019
- Microsoft Visual Studio 2022
Discovery Timeline
- 2025-10-14 - CVE-2025-55240 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-55240
Vulnerability Analysis
The vulnerability stems from improper access control within Visual Studio components. Access decisions do not adequately validate the requesting principal's authorization before granting access to protected resources or operations.
An authorized local attacker can abuse this weakness to perform actions reserved for higher-privileged users. The scope remains unchanged, meaning the attacker gains privileges within the vulnerable component's security context rather than crossing a trust boundary.
User interaction is required, which typically involves convincing a developer or another local user to run a crafted project, extension, or file within Visual Studio. Once triggered, the attacker obtains elevated privileges on the local host.
Root Cause
The root cause is classified as CWE-284: Improper Access Control. Visual Studio fails to enforce access restrictions on a protected operation or resource, allowing a lower-privileged user to invoke functionality that should be restricted.
Microsoft has not disclosed the specific subcomponent or code path affected. Refer to the Microsoft CVE-2025-55240 Advisory for authoritative technical details.
Attack Vector
The attack vector is local. An attacker must already possess valid credentials on the target system and induce a user to interact with a malicious artifact processed by Visual Studio. This artifact could be a crafted solution file, project template, package, or extension loaded by the integrated development environment.
No public proof-of-concept exploit is available at the time of publication, and the vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog.
No verified public exploit code is available. See the Microsoft Security Response Center advisory for vendor guidance.
Detection Methods for CVE-2025-55240
Indicators of Compromise
- Unexpected Visual Studio child processes spawned under elevated tokens, such as devenv.exe launching administrative binaries.
- Modification of files or registry keys outside the current user's normal profile shortly after a Visual Studio session begins.
- Installation or loading of unsigned or untrusted Visual Studio extensions (.vsix) from non-standard paths.
Detection Strategies
- Monitor process creation events (Windows Event ID 4688 / Sysmon Event ID 1) for devenv.exe and MSBuild launching privileged utilities such as cmd.exe, powershell.exe, or reg.exe.
- Alert on writes to protected directories including Program Files, ProgramData, and System32 originating from Visual Studio processes.
- Correlate token elevation events with Visual Studio activity to identify anomalous privilege transitions on developer workstations.
Monitoring Recommendations
- Baseline normal Visual Studio behavior per developer host and alert on deviations in child process trees.
- Track installation of Visual Studio extensions and MSBuild task assemblies, flagging additions outside approved software deployment channels.
- Review Windows Security and Application logs for repeated AccessCheck failures or User Account Control (UAC) prompts tied to devenv.exe.
How to Mitigate CVE-2025-55240
Immediate Actions Required
- Apply the security updates referenced in the Microsoft CVE-2025-55240 Advisory to all installations of Visual Studio 2017, 2019, and 2022.
- Inventory developer endpoints running Visual Studio and prioritize patching hosts with local user accounts that lack administrative isolation.
- Restrict local logon rights on developer workstations to trusted users only, reducing the pool of authorized attackers.
Patch Information
Microsoft has issued security updates for the affected Visual Studio versions. Administrators should install the latest cumulative updates through the Visual Studio Installer or through enterprise patch management. Consult the Microsoft Security Response Center advisory for the specific build numbers and download links.
Workarounds
- Avoid opening untrusted solution files, projects, or extensions from unverified sources until patches are applied.
- Enforce least privilege on developer accounts and disable local administrator rights where feasible.
- Require code signing and allow-listing for Visual Studio extensions loaded across the organization.
# Verify installed Visual Studio version using vswhere
"%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" -all -property installationVersion
# Launch Visual Studio Installer to apply available updates
"%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\setup.exe" update
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
