How severe is CVE-2021-43907?

CVE-2021-43907 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-43907 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43907?

CVE-2021-43907 affects Microsoft Windows Subsystem For Linux. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43907?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-43907 published?

CVE-2021-43907 was published on 2021-12-15 and last updated on 2026-06-17.

CVE-2021-43907

CVE-2021-43907 is a critical-severity vulnerability in Microsoft Windows Subsystem For Linux with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Windows Subsystem For Linux
Published: 2021-12-15
Last modified: 2026-06-17

Description

Visual Studio Code WSL Extension Remote Code Execution Vulnerability

Frequently asked questions

What is CVE-2021-43907?: Visual Studio Code WSL Extension Remote Code Execution Vulnerability
How severe is CVE-2021-43907?: CVE-2021-43907 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-43907 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43907?: CVE-2021-43907 affects Microsoft Windows Subsystem For Linux. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43907?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-43907 published?: CVE-2021-43907 was published on 2021-12-15 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43907

Affected products (1)

cpe:2.3:a:microsoft:windows_subsystem_for_linux:*:*:*:*:*:visual_studio_code:*:*

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