All CVE records
CVE-2023-21529 — Microsoft Exchange Server Deserialization of Untrusted Data Vulnerability
Known ransomware use
CISA KEV listed
Added April 13, 2026 Remediate by April 27, 2026
Description
Microsoft Exchange Server contains a deserialization of untrusted data that allows an authenticated attacker to achieve remote code execution.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Notes
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21529 ; https://nvd.nist.gov/vuln/detail/CVE-2023-21529
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