CVE Watch19 ago 2026

CVE-2021-26857

Microsoft Exchange Server Remote Code Execution Vulnerability

CVSS

7.8

Alto

EPSS

95.8%

p100

KEV

SÍ

3 nov 2021

Exploit Today

0-100

Publicado: 3 mar 2021 · Última mod.: 19 ago 2026 · CWE-502

EPSS · 30d

95.8%EPSS · 30 días95.8%

2026-09-162026-10-14

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-2021-26857

Descripción técnica

Microsoft Exchange Server Remote Code Execution Vulnerability

Referencias oficiales

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