Vulnerability in Microsoft Exchange Server
CVE-2026-62911
Authentication bypass by capture-replay in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.007 (50.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 50.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.007 · change: -0.003
Affected products
- Microsoft Exchange Server — versions 2016, 2019
- Microsoft Exchange Server Subscription Edition
- 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)
Public proof-of-concept exploits
References
- Microsoft Exchange Server Elevation of Privilege Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0
Frequently asked questions
- What is CVE-2026-62911?
- CVE-2026-62911 is a high-severity vulnerability in Microsoft Exchange Server, 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.
- Is CVE-2026-62911 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.