CVE-2021-26857CISA KEVEPSS p99.8%

CVE-2021-26857Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft / Exchange Server

Description

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

Scoring

EPSS94.01% probability of exploitation · percentile 99.8% · 2026-06-16T12:03:06Z

CISA KEV entry

Added to KEV: 2021-11-03

(incoming)1

TypeTargetConfidenceTier
KEVEntryMicrosoft Exchange Server Remote Code Execution Vulnerabilitykev-cve-2021-268570%live

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.

CVE
Microsoft Exchange Server Information Disclosure Vulnerability
CVE
CVE-2022-41082
CVE
CVE-2022-41080
CVE
Microsoft Exchange Server Privilege Escalation Vulnerability
CVE
Microsoft Exchange Server Security Feature Bypass Vulnerability
CVE
CVE-2026-45583
Sourced from NVD + CISA KEV + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.