CVE-2023-21529 — Security Box Score

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-2023-21529HIGH

Microsoft Exchange Server Remote Code Execution Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   L   N  U  H  H  H    8.8   .6210   99.1   YES

AFFECTED
  Product                                              Versions   Fixed
  Microsoft Exchange Server 2013 Cumulative Update 23  15.00.0 –  —
  Microsoft Exchange Server 2016 Cumulative Update 23  15.01.0 –  —
  Microsoft Exchange Server 2019 Cumulative Update 11  15.02.0 –  —
  Microsoft Exchange Server 2019 Cumulative Update 12  15.02.0 –  —

TIMELINE
  Dec 1   Reserved by microsoft
  Apr 13  Added to CISA KEV, remediation due 2026-04-27
  Apr 13  Published (CNA: microsoft)

CWE-502 · CNA: microsoft · CVSS v3.1 · 3 references · KEV due April 27, 2026

Description

Microsoft Exchange Server Remote Code Execution Vulnerability

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
December 1, 2022	Reserved	Reserved by microsoft
April 13, 2026	KEV ADDED	Added to CISA KEV, remediation due 2026-04-27
April 13, 2026	Published	Published (CNA: microsoft)

Affected

Affected products and packages — 4 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Microsoft	Microsoft Exchange Server 2013 Cumulative Update 23	—	15.00.0	—
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 23	—	15.01.0	—
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 11	—	15.02.0	—
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 12	—	15.02.0	—

Weaknesses

CWE-502

References (3)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21529 [vendor-advisory, patch]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-21529 [government-resource]
https://www.microsoft.com/en-us/security/blog/2026/04/06/storm-1175-focuses-gaze-on-vulnerable-web-facing-assets-in-high-tempo-medusa-ransomware-operations/ [vendor-advisory]

Authoritative record: CVE-2023-21529 at cve.org

Vendors: microsoft

Weaknesses: CWE-502

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2023-21529 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.