What is CVE-2023-21710?

CVE-2023-21710 is a high-severity vulnerability in Microsoft Exchange Server, classified under Deserialization of Untrusted Data. CVSS score: 7.2/10. Published 2023-02-14.

How severe is CVE-2023-21710?

High severity. CVSS v3 base score is 7.2 out of 10.

Deserialization in Microsoft Exchange Server

CVE-2023-21710

Microsoft Exchange Server Remote Code Execution Vulnerability

Vulnerability class: Insecure Deserialization

Published 2023-02-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.079 (94.5th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 94.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.079 · newest: 0.079 · change: 0.000

Affected products

Microsoft Exchange Server — versions 2016, 2019
Microsoft Exchange Server 2016 Cumulative Update 23 — versions 15.01.0
Microsoft Exchange Server 2019 Cumulative Update 11 — versions 15.02.0
Microsoft Exchange Server 2019 Cumulative Update 12 — versions 15.02.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

Microsoft Exchange Server Remote Code Execution Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2023-21710?: CVE-2023-21710 is a high-severity vulnerability in Microsoft Exchange Server, classified under Deserialization of Untrusted Data. CVSS score: 7.2/10. Published 2023-02-14.
How severe is CVE-2023-21710?: High severity. CVSS v3 base score is 7.2 out of 10.