CVE-2026-41109: Improper Neutralization of Special Elements in GitHub Copilot and Visual Studio
CVE-2026-41109 describes an improper neutralization of special elements in output used by a downstream component ('injection') vulnerability in GitHub Copilot and Visual Studio, allowing an unauthorized attacker to bypass a security feature over a network.
CVE-2026-41109 is a vulnerability affecting GitHub Copilot and Visual Studio. It involves an improper neutralization of special elements in output used by a downstream component, commonly referred to as an “injection” vulnerability. This flaw allows an unauthorized attacker to bypass a security feature over a network. The vulnerability was reported to Microsoft and assigned a CVSS v3.1 base score of 8.8, indicating a high severity. Exploitation of this vulnerability could lead to a compromise of security features within the affected applications.
Attack Chain
- Attacker crafts malicious input containing special elements (e.g., shell metacharacters, script tags).
- The malicious input is provided to GitHub Copilot or Visual Studio through a network interface.
- The application fails to properly neutralize the special elements within the input.
- The unneutralized input is passed to a downstream component for processing.
- The downstream component interprets the special elements as commands or instructions.
- The attacker bypasses the intended security feature due to the injected commands.
Impact
Successful exploitation of CVE-2026-41109 allows an attacker to bypass security features within GitHub Copilot and Visual Studio. The CVSS v3.1 score of 8.8 indicates a high potential for impact, including high confidentiality, integrity, and availability impact. The exact scope of the bypass depends on the specific security feature targeted and the capabilities of the downstream component.
Recommendation
- Apply the security updates provided by Microsoft for CVE-2026-41109 in GitHub Copilot and Visual Studio as soon as possible (reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41109).
- Deploy the Sigma rule to detect potential exploitation attempts targeting CVE-2026-41109.
Detection coverage 2
Detects CVE-2026-41109 Exploitation Attempt - Suspicious Input to GitHub Copilot/Visual Studio
highDetects CVE-2026-41109 exploitation attempt — Detects suspicious input containing special characters that could be used to bypass security features in GitHub Copilot or Visual Studio.
Detects CVE-2026-41109 Exploitation Attempt - Downstream Component Injection
mediumDetects CVE-2026-41109 exploitation attempt — Detects potential injection attempts in downstream components by monitoring for unusual command execution patterns following input from GitHub Copilot/Visual Studio.
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