Vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23
CVE-2026-55006
Insufficient granularity of access control in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
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.
Affected products
- Microsoft Exchange Server 2016 Cumulative Update 23 — versions 15.01.0.0
- Microsoft Exchange Server 2019 Cumulative Update 14 — versions 15.02.0.0
- Microsoft Exchange Server 2019 Cumulative Update 15 — versions 15.02.0.0
- Microsoft Exchange Server Subscription Edition Rtm — versions 15.02.0.0
Weakness classification (CWE)
References
- secure@microsoft.com (vendor-advisory, patch)
Frequently asked questions
- What is CVE-2026-55006?
- CVE-2026-55006 is a high-severity vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23, classified under CWE-1220. CVSS score: 7.8/10. Published 2026-07-14.
- How severe is CVE-2026-55006?
- High severity. CVSS v3 base score is 7.8 out of 10.