SB2026021066 - Spoofing attack in Microsoft Exchange Server



SB2026021066 - Spoofing attack in Microsoft Exchange Server

Published: February 10, 2026 Updated: February 19, 2026

Security Bulletin ID SB2026021066
Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Spoofing attack (CVE-ID: CVE-2026-21527)

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of user-supplied data within the InterceptorSmtpAgent class. A remote attacker can perform spoofing attack against Exchange users. 


Remediation

Install update from vendor's website.