How severe is CVE-2021-28450?

CVE-2021-28450 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2021-28450 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28450?

CVE-2021-28450 primarily affects Microsoft Sharepoint Foundation. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-28450?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-28450 published?

CVE-2021-28450 was published on 2021-04-13 and last updated on 2026-06-17.

CVE-2021-28450

CVE-2021-28450 is a medium-severity vulnerability in Microsoft Sharepoint Foundation with a CVSS 3.x base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.0)
CVSS v2: 4.0
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Sharepoint Foundation
Published: 2021-04-13
Last modified: 2026-06-17

Description

Microsoft SharePoint Denial of Service Vulnerability

Frequently asked questions

What is CVE-2021-28450?: Microsoft SharePoint Denial of Service Vulnerability
How severe is CVE-2021-28450?: CVE-2021-28450 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2021-28450 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28450?: CVE-2021-28450 primarily affects Microsoft Sharepoint Foundation. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-28450?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-28450 published?: CVE-2021-28450 was published on 2021-04-13 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28450

Affected products (4)

cpe:2.3:a:microsoft:sharepoint_foundation:2010:sp2:*:*:*:*:*:*
cpe:2.3:a:microsoft:sharepoint_server:2013:sp1:*:*:enterprise:*:*:*
cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*
cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*

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