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CVE-2021-33766

Known Exploited (CISA KEV)HIGH

7.3

CVSS Severity Score

EPSS Score39.3890%

EPSS Percentile96.36th

PublishedJul 14, 2021

Last ModifiedOct 29, 2025

Vulnerability Description

Microsoft Exchange Server Information Disclosure Vulnerability

Affected Platforms (CPE)

📦

Microsoft

Exchange Server

= 2013

📦

Microsoft

Exchange Server

= 2016

📦

Microsoft

Exchange Server

= 2016

📦

Microsoft

Exchange Server

= 2019

📦

Microsoft

Exchange Server

= 2019

References & Advisories

🔗 https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33766

🔗 https://www.zerodayinitiative.com/advisories/ZDI-21-798/

🔗 https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33766

🔗 https://www.zerodayinitiative.com/advisories/ZDI-21-798/

🔗 https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-33766

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