boxscore/security
CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-33766HIGH
Microsoft Exchange Server Information Disclosure Vulnerability
  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  L  L  L    7.3   .9818   99.9   YES
AFFECTED
  Product                                              Versions   Fixed
  Microsoft Exchange Server 2013 Cumulative Update 23  15.00.0 –  —
  Microsoft Exchange Server 2016 Cumulative Update 19  15.01.0 –  —
  Microsoft Exchange Server 2016 Cumulative Update 20  15.01.0 –  —
  Microsoft Exchange Server 2019 Cumulative Update 8   15.02.0 –  —
  Microsoft Exchange Server 2019 Cumulative Update 9   15.02.0 –  —
TIMELINE
  May 28  Reserved by microsoft
  Jan 18  Added to CISA KEV, remediation due 2022-02-01
  Jan 18  Published (CNA: microsoft)
CNA: microsoft · CVSS v3.1 · 4 references · NVD status: Analyzed · KEV due February 1, 2022

Description

Microsoft Exchange Server Information Disclosure Vulnerability

Lifecycle

Complete event history — 3 events, chronological
DateEventDetail
May 28, 2021ReservedReserved by microsoft
January 18, 2022KEV ADDEDAdded to CISA KEV, remediation due 2022-02-01
January 18, 2022PublishedPublished (CNA: microsoft)

Affected

Affected products and packages — 5 rows
VendorProduct / PackageEcosystemVersion introducedFixed
MicrosoftMicrosoft Exchange Server 2013 Cumulative Update 23—15.00.0—
MicrosoftMicrosoft Exchange Server 2016 Cumulative Update 19—15.01.0—
MicrosoftMicrosoft Exchange Server 2016 Cumulative Update 20—15.01.0—
MicrosoftMicrosoft Exchange Server 2019 Cumulative Update 8—15.02.0—
MicrosoftMicrosoft Exchange Server 2019 Cumulative Update 9—15.02.0—

References (4)

Related

Authoritative record: CVE-2021-33766 at cve.org

Vendors: microsoft

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-33766 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.