What is the CVSS score of CVE-2021-33766?

CVE-2021-33766 has a CVSS 3.1 base score of 7.3 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. EPSS exploitation probability: 97.5%.

Is there a public PoC exploit available for CVE-2021-33766?

Yes, a public proof-of-concept exploit is available for CVE-2021-33766. Prioritise patching immediately. EPSS: 97.5%.

Is there a patch available for CVE-2021-33766?

Yes, a patch is available for CVE-2021-33766. Update the affected software to the latest version immediately.

Exchange Server CVE-2021-33766

HIGH

2021-07-14 secure@microsoft.com

Microsoft Information Disclosure Exchange Server

7.3

CVSS 3.1 · Vendor: microsoft

Severity by source

Vendor (microsoft) PRIMARY

7.3 HIGH

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

Primary rating from Vendor (microsoft) · only source for this CVE.

CVSS VectorVendor: microsoft

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low

Lifecycle Timeline

Added to CISA KEV

Jul 14, 2026 - 04:22 CISA

CVE Published

Jul 14, 2021 - 18:15 cve.org

HIGH 7.3

DescriptionCVE.org

Microsoft Exchange Server Information Disclosure Vulnerability

AnalysisAI

Microsoft Exchange Server Information Disclosure Vulnerability. Rated high severity (CVSS 7.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity.

Technical ContextAI

Microsoft Exchange Server Information Disclosure Vulnerability Affected products include: Microsoft Exchange Server.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

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CVE-2021-33766 vulnerability details – vuln.today

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