CVE-2023-21529

HIGH KEV

Microsoft Exchange Server - Remote Code Execution

Title source: llm

CVE-2023-21529 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added April 13, 2026.

Microsoft Exchange Server Remote Code Execution Vulnerability

Core 3

Core References

Third Party Advisory, US Government Resource

Vendor Advisory

Patch, Vendor Advisory vendor-advisory

CVSS v3 8.8

EPSS 0.2704

EPSS Percentile 96.5%

Attack Vector NETWORK

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

Vulnrichment

Exploitation active

Automatable no

Technical Impact total

CISA KEV 2026-04-13

VulnCheck KEV 2026-04-06

ENISA EUVD EUVD-2023-25697

CWE

CWE-502

Status published

Products (7)

microsoft/exchange_server 2013 cumulative_update_23

microsoft/exchange_server 2016 cumulative_update_23

microsoft/exchange_server 2019 cumulative_update_11 (2 CPE variants)

Microsoft/Microsoft Exchange Server 2013 Cumulative Update 23 15.00.0 - 15.00.1497.047

Microsoft/Microsoft Exchange Server 2016 Cumulative Update 23 15.01.0 - 15.01.2507.021

Microsoft/Microsoft Exchange Server 2019 Cumulative Update 11 15.02.0 - 15.02.0986.041

Microsoft/Microsoft Exchange Server 2019 Cumulative Update 12 15.02.0 - 15.02.1118.025

Published Feb 14, 2023

KEV Added Apr 13, 2026

Tracked Since Feb 18, 2026