Is CVE-2021-42306 in the CISA KEV catalog?

No. CVE-2021-42306 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-42306?

CVE-2021-42306 has a CVSS v3 base score of 8.1 (HIGH).

What is the EPSS score for CVE-2021-42306?

CVE-2021-42306 has an EPSS score of 3.08% (86th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-42306?

Upgrade azure active directory to 2021-10-30 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2021-42306

HIGHEPSS 86th pctl

8.1

CVSS v3

NVD

Description

An information disclosure vulnerability manifests when a user or an application uploads unprotected private key data as part of an authentication certificate keyCredential on an Azure AD Application or Service Principal (which is not recommended). This vulnerability allows a user or service in the tenant with application read access to read the private key data that was added to the application. Azure AD addressed this vulnerability by preventing disclosure of any private key values added to the application. Microsoft has identified services that could manifest this vulnerability, and steps that customers should take to be protected. Refer to the FAQ section for more information. For more details on this issue, please refer to the MSRC Blog Entry.

CWE-522

How to fix

Remediation Available

azure active directoryNVD

Affected:< 2021-10-30Fixed in:2021-10-30CVE-2021-42306derived from NVD

azure active site recoveryNVD

Affected:< 2021-11-01Fixed in:2021-11-01CVE-2021-42306derived from NVD

azure automationNVD

Affected:< 2021-10-15Fixed in:2021-10-15CVE-2021-42306derived from NVD

azure migrateNVD

Affected:< 2021-11-02Fixed in:2021-11-02CVE-2021-42306derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Exploit Intelligence

3.08%probability of exploitation in 30 days

86thpercentile

Elevated risk: more likely to be exploited than 86% of all known CVEs.

References

Patch1

portal.msrc.microsoft.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-24.