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Case File

CVE-2021-26855

CRITICAL · CVSS 9.1 EPSS 100.00% CISA KEV · Actively Exploited Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-03-03 · Last synced 2026-08-04

CyberRota Analysis

AI analysis pending.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
remote code execution code execution
External Security References
packetstormsecurity.com ↗ packetstormsecurity.com ↗ packetstormsecurity.com ↗ packetstormsecurity.com ↗

Note: these links are listed for security research and verification purposes only.

CISA KEV Details

Status: This CVE is listed in CISA's Known Exploited Vulnerabilities catalog.

Ransomware use: Known

Added to KEV: 2021-11-03

Required action: Apply updates per vendor instructions.

CVE
CVE-2021-26855
Severity
CRITICAL
CVSS
9.1
EPSS
100.00%
Microsoft Exchange

Original NVD Description

Microsoft Exchange Server Remote Code Execution Vulnerability