What is CVE-2026-87692?

CVE-2026-87692 is a high-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under Deserialization of Untrusted Data. CVSS score: 7.8/10. Published 2026-10-13.

How severe is CVE-2026-87692?

High severity. CVSS v3 base score is 7.8 out of 10.

Deserialization in Microsoft Exchange Server 2016 Cumulative Update 23

CVE-2026-87692

Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.

Vulnerability class: Insecure Deserialization

Published 2026-10-13 · last modified 2026-10-13.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-87692 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-87692?: CVE-2026-87692 is a high-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under Deserialization of Untrusted Data. CVSS score: 7.8/10. Published 2026-10-13.
How severe is CVE-2026-87692?: High severity. CVSS v3 base score is 7.8 out of 10.