ZDI-26-082: Microsoft Exchange InterceptorSmtpAgent Reliance on Untrusted Inputs Security Feature Bypass Vulnerability

Published Feb 12, 2026
·
Updated

This vulnerability allows remote attackers to bypass a security feature on affected installations of Microsoft Exchange. Authentication is not required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 5.3. The following CVEs are assigned: CVE-2026-21527.

Affected Software

1 affected component
Microsoft Exchange

Event History

Feb 12, 2026
Advisory Published
via ZDI·06:00 AM
Data Sourced
via ZDI·06:00 AM
Description
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Frequently Asked Questions

1

What is the severity of ZDI-26-082?

The severity of ZDI-26-082 is high due to the ability of remote attackers to bypass security measures without authentication.

2

How do I fix ZDI-26-082?

To fix ZDI-26-082, ensure that you apply the latest security patches released by Microsoft for affected versions of Exchange.

3

Which Microsoft Exchange versions are affected by ZDI-26-082?

All supported versions of Microsoft Exchange are potentially affected by ZDI-26-082.

4

What type of attack can exploit ZDI-26-082?

ZDI-26-082 can be exploited through remote attacks that bypass security controls in the Exchange InterceptorSmtpAgent.

5

Is authentication required to exploit ZDI-26-082?

No, authentication is not required to exploit ZDI-26-082, making it particularly dangerous.

Contact

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