How severe is CVE-2021-26434?

CVE-2021-26434 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-26434 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26434?

CVE-2021-26434 primarily affects Microsoft Visual Studio 2017. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26434?

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

When was CVE-2021-26434 published?

CVE-2021-26434 was published on 2021-09-15 and last updated on 2026-06-17.

CVE-2021-26434

CVE-2021-26434 is a high-severity vulnerability in Microsoft Visual Studio 2017 with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-732.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-732
Affected product: Microsoft Visual Studio 2017
Published: 2021-09-15
Last modified: 2026-06-17

Description

Visual Studio Elevation of Privilege Vulnerability

Frequently asked questions

What is CVE-2021-26434?: Visual Studio Elevation of Privilege Vulnerability
How severe is CVE-2021-26434?: CVE-2021-26434 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26434 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26434?: CVE-2021-26434 primarily affects Microsoft Visual Studio 2017. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26434?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-26434 published?: CVE-2021-26434 was published on 2021-09-15 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:microsoft:visual_studio_2017:*:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:visual_studio_2019:*:*:*:*:*:*:*:*

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