CVE-2026-107759: WPO365 | MICROSOFT 365 GRAPH MAILER <= 6.2 - Unauthenticated Stored Cross-Site Scripting via Email Subject via wp_mail

Q: Which deployments are most exposed to this issue?

WordPress sites using WPO365 | MICROSOFT 365 GRAPH MAILER version 6.2 or earlier are exposed when Graph Mailer is enabled and OAuth authorization has not been completed. This is the default state immediately after plugin activation, particularly where a mail-sending form forwards a visitor-controlled subject.

Q: What does an attacker need to exploit it?

An attacker does not need authentication or user interaction to submit the payload. They need access to a mail-sending feature, such as a Contact Form 7 form, that passes a submitter-controlled subject through wp_mail/PHPMailer while the affected Graph Mailer configuration is enabled.

Q: When would the injected script execute?

The script is stored and executes when a user accesses an injected page. Successful exploitation can affect confidentiality and integrity, as reflected by the CVSS vector’s low confidentiality and integrity impacts.

Published Oct 31, 2026

Updated

The WPO365 | MICROSOFT 365 GRAPH MAILER plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Subject (via wpmail/PHPMailer, e.g. CF7 your-subject)' parameter in all versions up to, and including, 6.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The payload is stored without authentication via any mail-sending feature that forwards a submitter-controlled subject (e.g. a Contact Form 7 form) when the Graph Mailer is enabled but OAuth authorization has not been completed, a default state immediately after plugin activation.

Event History

Oct 31, 2026

CVE Published

via MITRE·07:46 AM

Data Sourced

via MITRE·07:46 AM

DescriptionSeverityWeakness

Data Sourced

via NVD·08:16 AM

DescriptionSeverityWeakness

Frequently Asked Questions

Which deployments are most exposed to this issue?

WordPress sites using WPO365 | MICROSOFT 365 GRAPH MAILER version 6.2 or earlier are exposed when Graph Mailer is enabled and OAuth authorization has not been completed. This is the default state immediately after plugin activation, particularly where a mail-sending form forwards a visitor-controlled subject.

What does an attacker need to exploit it?

An attacker does not need authentication or user interaction to submit the payload. They need access to a mail-sending feature, such as a Contact Form 7 form, that passes a submitter-controlled subject through wp_mail/PHPMailer while the affected Graph Mailer configuration is enabled.

When would the injected script execute?

The script is stored and executes when a user accesses an injected page. Successful exploitation can affect confidentiality and integrity, as reflected by the CVSS vector’s low confidentiality and integrity impacts.

CVE-2026-107759: WPO365 | MICROSOFT 365 GRAPH MAILER <= 6.2 - Unauthenticated Stored Cross-Site Scripting via Email Subject via wp_mail

Event History

Frequently Asked Questions

Which deployments are most exposed to this issue?

What does an attacker need to exploit it?

When would the injected script execute?

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Frequently Asked Questions

Which deployments are most exposed to this issue?

What does an attacker need to exploit it?

When would the injected script execute?