Live › vulnerability › CVE-2021-34523
Go to dashboardMicrosoft Exchange Server has a privilege escalation flaw that CISA lists as actively exploited, with ransomware use noted in its catalog entry. An attacker who gets a foothold can gain higher privileges on the Exchange server.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 19:11 UTC, 3h before NVD. All times on this page are UTC.
Apply updates per vendor instructions.
| Product | Ecosystem | Affected | Fixed in |
|---|---|---|---|
| Microsoft Exchange Server | vendor | – | – |
Unknown from the sources. In the analyst’s queue.
Apply the Microsoft updates for Exchange Server per vendor instructions, as CISA requires; the specific patch version is unknown from these sources.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
Microsoft Exchange Server contains an unspecified vulnerability that allows for privilege escalation.
CISA required action: Apply updates per vendor instructions.
This page as .md · .json · in your agent: get_signal("CVE-2021-34523")
CISA KEV catalog, Creative Commons 0 · EPSS scores by FIRST, used with attribution · NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.