Vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23

CVE-2026-62911

Authentication bypass by capture-replay in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-62911?
CVE-2026-62911 is a high-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under Authentication Bypass by Capture-replay. CVSS score: 8.0/10. Published 2026-08-11.
How severe is CVE-2026-62911?
High severity. CVSS v3 base score is 8.0 out of 10.