Cyber Resilience

CVE-2026-21256

RCE in Microsoft Visual Studio 2022 17.14.0 – 17.14.26

Published
10 February 2026
Modified
11 February 2026
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.011 63th percentile
Risk Priority 66 floored blend · peak EPSS

Summary

CVE-2026-21256 is a high-severity Command Injection (CWE-77) vulnerability in Microsoft Visual Studio 2022. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 37% of CVEs by exploit likelihood; 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 map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-21256, published on 2026-02-10, is an improper neutralization of special elements used in a command, resulting in command injection (CWE-77, CWE-94). This vulnerability affects GitHub Copilot and Visual Studio, enabling an unauthorized attacker to execute code over a network. It carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating high severity due to network accessibility, low attack complexity, and significant impacts.

An unauthorized attacker with no required privileges can exploit the vulnerability remotely over the network, though it requires user interaction to trigger. Successful exploitation allows arbitrary code execution on the affected system, compromising confidentiality, integrity, and availability to a high degree.

The Microsoft Security Response Center (MSRC) provides an update guide for CVE-2026-21256 at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21256, which details mitigation strategies and available patches.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Improper neutralization of special elements used in a command ('command injection') in GitHub Copilot and Visual Studio allows an unauthorized attacker to execute code 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 Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.002 AppleScript Execution
Adversaries may abuse AppleScript for execution.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2013-3906Same vendor: Microsoft
CVE-2024-21643Same vendor: Microsoft
CVE-2009-0556Same vendor: Microsoft
CVE-2024-43469Same vendor: Microsoft
CVE-2023-36572Same vendor: Microsoft
CVE-2024-29991Same vendor: Microsoft
CVE-2026-26030Same vendor: Microsoft
CVE-2026-21537Same vendor: Microsoft
CVE-2023-33157Same vendor: Microsoft
CVE-2023-35333Same vendor: Microsoft

Affected Assets

microsoft
visual studio 2022
17.14.0 — 17.14.26

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.3
  • V1.2.5
  • V1.2.8
  • V1.2.9

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover command-construction flaws before deployment.

Input validation directly stops construction of commands from untrusted data containing special elements.

Least privilege limits the damage an injected code fragment can perform once executed.

Requiring documented secure development standards and tools enforces use of safe code-generation APIs and escaping.

Secure engineering principles include proper neutralization and safe command construction practices.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and neutralization that prevent command injection.

DE.CM-09 partial match
prevents

Runtime monitoring of software and data can detect anomalous command execution resulting from injection.

ID.RA-01 partial match
prevents

Identifying recorded vulnerabilities enables remediation of command-injection flaws before exploitation.

PR.DS-10 none match
prevents

PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure coding standards require proper escaping and parameterization of commands, directly eliminating CWE-77.

finds

Security testing in development catches command-injection vulnerabilities before release.

prevents

Secure development life cycle mandates input validation and command construction practices that directly prevent command injection.

prevents

Application security requirements explicitly call for controls against injection flaws including command injection.

prevents

Secure architecture principles reduce the attack surface but do not prescribe the specific neutralization techniques needed.

none

Environment separation limits the blast radius of an exploited command injection but does not prevent the flaw itself.

References