CVE-2026-107759: WPO365 stored cross-site scripting (XSS) vulnerability

high 7.2 published 2026-10-31 · updated 2026-11-02

Affected versions: 6.2 and older
Fixed in: 6.3 *
Latest version: 6.3
Severity: High · CVSS 7.2
Active installs: 10,000+
Type: Stored cross-site scripting (XSS)

* The source does not name a fixed version; this is the first wordpress.org release after the last affected version.

What an attacker needs

Access: None. No account or login is needed.

CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

What to do now

Update WPO365 to 6.3 or newer: Dashboard → Updates, or Plugins → “update now”.
If you cannot update right away, deactivate it until you can.
Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
Not sure which version you run? Check your version against every known WPO365 issue. With WP-CLI: wp plugin get wpo365-msgraphmailer --field=version.
If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.

The advisory

The WPO365 | MICROSOFT 365 GRAPH MAILER plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Subject (via wp_mail/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.

Description from the CVE record, published by Wordfence (the CVE Numbering Authority), via the NVD entry for CVE-2026-107759.

References

NVD CVE-2026-107759 nvd.nist.gov
Wordfence advisory www.wordfence.com
Code change (fix) plugins.trac.wordpress.org
Plugin source plugins.trac.wordpress.org

Ran an affected version? Check your site for signs of a hack

The free scan reads the public side of your site and looks for spam pages, hidden redirects, injected scripts and blacklist entries. No login, no install, about a minute.

Where this data comes from

CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Versions and install counts: wordpress.org/plugins/wpo365-msgraphmailer (Plugins API), fetched 2026-11-04.
The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.