How severe is CVE-2021-26429?

CVE-2021-26429 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2021-26429 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26429?

CVE-2021-26429 affects Microsoft Azure Sphere. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26429?

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-2021-26429 published?

CVE-2021-26429 was published on 2021-08-12 and last updated on 2026-06-17.

CVE-2021-26429

CVE-2021-26429 is a high-severity vulnerability in Microsoft Azure Sphere with a CVSS 3.x base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 7.7)
CVSS v2: 4.6
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Azure Sphere
Published: 2021-08-12
Last modified: 2026-06-17

Description

Azure Sphere Elevation of Privilege Vulnerability

Frequently asked questions

What is CVE-2021-26429?: Azure Sphere Elevation of Privilege Vulnerability
How severe is CVE-2021-26429?: CVE-2021-26429 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2021-26429 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26429?: CVE-2021-26429 affects Microsoft Azure Sphere. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26429?: 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-2021-26429 published?: CVE-2021-26429 was published on 2021-08-12 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26429

Affected products (1)

cpe:2.3:a:microsoft:azure_sphere:*:*:*:*:*:*:*:*

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