CVE-2026-21256 | GitHub Copilot and Visual Studio Remote Code Execution Vulnerability

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.

Published: 2026-02-10 Last update: 2026-02-11 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-21256 is rated Low Risk (39.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.04%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-21256

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-13 0.05% 0.04% -0.01%
2 2026-02-12 0.05% 0.05% +0.00%
3 2026-02-11 0.05%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-21256

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]

Weakness enumeration for CVE-2026-21256

Affected software / configurations for CVE-2026-21256

Vendor Product Version Raw CPE
microsoft visual_studio_2022 >= 17.14.0, < 17.14.26 cpe:2.3:a:microsoft:visual_studio_2022:*:*:*:*:*:-:*:*

References for CVE-2026-21256

cvelogic Threat Intelligence