Vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23

CVE-2025-59249

Weak authentication in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.

EPSS: 0.001 (29.6th percentile) — read the EPSS interpretation.

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/E:U/RL:O/RC:C.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-59249?
CVE-2025-59249 is a high-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under Weak Authentication. CVSS score: 8.8/10. Published 2025-10-14.
How severe is CVE-2025-59249?
High severity. CVSS v3 base score is 8.8 out of 10.