CVE Watch—

CVE-2021-26855

Microsoft Exchange Server Remote Code Execution Vulnerability

CVSS

—

Sin CVSS

EPSS

100.0%

p100

KEV

SÍ

3 nov 2021

Exploit Today

0-100

Publicado: — · Última mod.: —

EPSS · 30d

100.0%EPSS · 30 días100.0%

2026-06-302026-07-16

Ficha del catálogo KEV

Producto

Microsoft / Exchange Server

Vulnerabilidad

Microsoft Exchange Server Remote Code Execution Vulnerability

Añadido a KEV

3 nov 2021

Remediar antes de

3 may 2022

Uso conocido en ransomware

Sí

Descripción resumida

Microsoft Exchange Server contains an unspecified vulnerability that allows for remote code execution. This vulnerability is part of the ProxyLogon exploit chain.

Acción requerida

Apply updates per vendor instructions.

Notas

Reference CISA's ED 21-02 (https://www.cisa.gov/news-events/directives/ed-21-02-mitigate-microsoft-exchange-premises-product-vulnerabilities) for further guidance and requirements. Note: The due date for addressing this vulnerability aligns with the requirements outlined in ED 21-02. https://nvd.nist.gov/vuln/detail/CVE-2021-26855

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