CVE-2026-21257
Published: 10 February 2026
Summary
CVE-2026-21257 is a high-severity Command Injection (CWE-77) vulnerability in Microsoft Visual Studio 2022. Its CVSS base score is 8.0 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 14.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as Enterprise AI Assistants; in the Supply Chain and Deployment risk domain.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-21257 is an improper neutralization of special elements used in a command (CWE-77), enabling command injection in GitHub Copilot and Visual Studio. This vulnerability allows an authorized attacker to elevate privileges over a network. It was published on 2026-02-10T18:16:27.483 with a CVSS v3.1 score of 8.0 (AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H), reflecting high severity due to network vector, low complexity, low privilege requirement, user interaction need, and high impacts across confidentiality, integrity, and availability.
Attackers require low privileges (PR:L), such as an authenticated user in the affected environment, and must leverage user interaction (UI:R) to exploit remotely (AV:N). By injecting malicious commands through unneutralized special elements in GitHub Copilot suggestions or Visual Studio command handling, they can achieve privilege escalation, resulting in high-level control over the system (C:H/I:H/A:H) without scope changes (S:U).
The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21257 outlines mitigation steps, including available patches and update guidance for GitHub Copilot and Visual Studio. Practitioners should apply these vendor updates promptly to remediate the command injection flaw.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-7327
Vulnerability details
Improper neutralization of special elements used in a command ('command injection') in GitHub Copilot and Visual Studio allows an authorized attacker to elevate privileges over a network.
- CWE(s)
AI Security AnalysisAI
- AI Category
- Enterprise AI Assistants
- Risk Domain
- Supply Chain and Deployment
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: github copilot
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CWE-77 command injection directly enables arbitrary command execution (T1059) and is exploited for privilege escalation (T1068) with network reachability.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SI-10 directly addresses command injection by requiring validation and neutralization of special elements in inputs to GitHub Copilot and Visual Studio commands.
SI-2 mandates timely remediation of flaws like this command injection vulnerability through vendor patches for GitHub Copilot and Visual Studio.
AC-6 least privilege limits the impact of privilege escalation achieved via command injection by authorized low-privilege attackers.