CVE-2023-21529

HIGHCVSS 8.8Known Exploited

CISA Known Exploited Vulnerability

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21529 ; https://nvd.nist.gov/vuln/detail/CVE-2023-21529

Remediation deadline: April 27, 2026

Ransomware use: Known

Description

Microsoft Exchange Server contains a deserialization of untrusted data that allows an authenticated attacker to achieve remote code execution.

Timeline

Published:February 14th, 2023 8:15 PM

Last modified:August 19th, 2026 5:18 PM

Added to KEV:April 13th, 2026

CVSS Scoring

CVSS v3: 8.8 (HIGH)

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

Affected Software

From NVD CPE configuration data

Vendors

microsoft

Products

exchange_server

Weaknesses (CWE)

References & Reports

Advisories, patches, and third-party reports

Source: NIST NVD · Data may lag official sources by up to one minute