CRITICALCVSS 9.0Actively exploited · CISA KEV since 2021-11-03Vulnerability

CVE-2021-34523

Microsoft Exchange Server contains an unspecified vulnerability that allows for privilege escalation.

Properties

Euvd product
Microsoft Exchange Server 2019 Cumulative Update 8, Microsoft Exchange Server 2013 Cumulative Update 23, Microsoft Exchange Server 2016 Cumulative Update 20, Microsoft Exchange Server 2016 Cumulative Update 19, Microsoft Exchange Server 2019 Cumulative Update 9
Vulnerability name
Microsoft Exchange Server Privilege Escalation Vulnerability
First seen
2026-08-10T15:11:21+00:00
Cvss score
9
Epss score
0.9999
Last seen
2026-10-19T12:00:27+00:00
Due date
2021-11-17
Euvd assigner
microsoft
Retrieved at
2026-10-21T01:24:47+00:00
Exploited euvd since
2021-11-03T00:00:00+00:00
Src batch id
epss_history-20261020T103617Z-728ddd
Source url
https://epss.empiricalsecurity.com/epss_scores-2026-10-19.csv.gz
Date added
2021-11-03
Euvd base score version
3.1
Score
9
Fetched at
2026-10-20T10:36:20+00:00
Euvd vendor
Microsoft
Cvss vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
In Signal since
initial import (Sep 2026)
Euvd base score
9

Related Entities (11)

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CVE-2021-34523 (CVSS 9) — Ninja Signal Threat Intelligence | Ninja Signal