Live › vulnerability › CVE-2021-42321
Go to dashboardMicrosoft Exchange Server has a flaw in how it validates cmdlet arguments, letting an authenticated user run code on the server. The flaw is confirmed exploited in the wild and is listed in CISA's Known Exploited Vulnerabilities catalog.
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 | vendor | – | – |
Unknown from the sources. In the analyst’s queue.
Apply the Microsoft updates for Exchange Server per vendor instructions (CISA required action); the specific cumulative update versions are not in the sources.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
An authenticated attacker could leverage improper validation in cmdlet arguments within Microsoft Exchange and perform remote code execution.
CISA required action: Apply updates per vendor instructions.
This page as .md · .json · in your agent: get_signal("CVE-2021-42321")
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.