CVE-2021-31207
Microsoft Exchange Server Security Feature Bypass Vulnerability
CVSS
—
No CVSS
EPSS
99.8%
p100
KEV
YES
Nov 3, 2021
Exploit Today
80
0-100
Published: — · Last modified: —
99.8%EPSS · 30 days99.8%
2026-06-302026-07-16
Product
Microsoft / Exchange Server
Vulnerability
Microsoft Exchange Server Security Feature Bypass Vulnerability
Added to KEV
Nov 3, 2021
Remediate by
Nov 17, 2021
Known ransomware use
Yes
Summary description
Microsoft Exchange Server contains an unspecified vulnerability that allows for security feature bypass.
Required action
Apply updates per vendor instructions.
Notes
https://nvd.nist.gov/vuln/detail/CVE-2021-31207
CVECVSSEPSSKEVRExploitTitleMod.
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