What is CVE-2026-96940?

CVE-2026-96940 is a high-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under Weak Authentication. CVSS score: 8.8/10. Published 2026-10-02.

How severe is CVE-2026-96940?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23

CVE-2026-96940

Weak authorization in Microsoft Exchange Server allows an authenticated attacker to elevate privileges over a network.

Published 2026-10-02 · last modified 2026-10-03.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/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-1390 — Weak Authentication

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96940 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-96940?: CVE-2026-96940 is a high-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under Weak Authentication. CVSS score: 8.8/10. Published 2026-10-02.
How severe is CVE-2026-96940?: High severity. CVSS v3 base score is 8.8 out of 10.