CVE

CVE-2023-21529

P1⬤ KNOWN RANSOMWARE USE

Microsoft Exchange Server Deserialization of Untrusted Data Vulnerability

Microsoft · Exchange Server

Date added (CISA)

2026-04-13

Remediation due

2026-04-27

Known ransomware use

Yes

Remediation priority

P1 — known ransomware use · past CISA due date

Description

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