What is CVE-2023-36777?

CVE-2023-36777 is a medium-severity vulnerability in Microsoft Exchange Server, classified under Deserialization of Untrusted Data. CVSS score: 5.7/10. Published 2023-09-12.

How severe is CVE-2023-36777?

Medium severity. CVSS v3 base score is 5.7 out of 10.

Deserialization in Microsoft Exchange Server

CVE-2023-36777

Microsoft Exchange Server Information Disclosure Vulnerability

Vulnerability class: Insecure Deserialization

Published 2023-09-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.7 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.520 (99.0th percentile), scored 2026-10-31.

High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.520 · newest: 0.520 · 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 12 — versions 15.02.0
Microsoft Exchange Server 2019 Cumulative Update 13 — versions 15.02.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2023-36777 (vendor-advisory, Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2023-36777?: CVE-2023-36777 is a medium-severity vulnerability in Microsoft Exchange Server, classified under Deserialization of Untrusted Data. CVSS score: 5.7/10. Published 2023-09-12.
How severe is CVE-2023-36777?: Medium severity. CVSS v3 base score is 5.7 out of 10.