CVE-2026-21257
8.0Microsoft · Visual Studio
A command injection vulnerability in GitHub Copilot and Microsoft Visual Studio allows an authorized attacker to elevate privileges over a network.
Executive summary
A critical command injection vulnerability in Microsoft Visual Studio and GitHub Copilot could allow an authenticated attacker to achieve unauthorized privilege escalation.
Vulnerability
The flaw is a command injection vulnerability (CWE-77) triggered by improper neutralization of special elements in commands, requiring the attacker to possess authenticated access to the network to exploit the system.
Business impact
The vulnerability carries a CVSS score of 8.0, indicating a high severity risk due to the potential for privilege escalation. Successful exploitation could allow an attacker to execute arbitrary commands with elevated permissions, leading to full system compromise, data exfiltration, or unauthorized modification of critical development environments.
Remediation
Immediate Action: Update Microsoft Visual Studio to the latest patched version as specified in the Microsoft Security Update Guide.
Proactive Monitoring: Monitor system logs for unusual command execution patterns or unauthorized attempts to initiate processes originating from the Visual Studio environment.
Compensating Controls: Ensure that users operate with the principle of least privilege, minimizing the impact if a local account is compromised, and utilize network segmentation to restrict access to development servers.
Exploitation status
Public Exploit Available: No (exploit_available: false)
Analyst recommendation
Given the high CVSS score and the nature of the vulnerability, organizations should prioritize patching their Visual Studio installations immediately. Failure to address this flaw could allow malicious actors to move laterally or escalate their access within the development infrastructure, posing a significant risk to the integrity of the software development lifecycle.