CVE-2026-2559
The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the function in all versions up to, and incl…
Published Mar 18, 2026 · updated Jun 17, 2026
The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the function in all versions up to, and including, 3.8.0. This is due to the function being hooked to without any check or nonce verification. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the site's Office 365 OAuth mail configuration (access token, refresh token, and user email) via a crafted URL. The configuration option is used during wizard setup of Microsoft365 SMTP, only available in the Pro option of the plugin. This could cause an Administrator to believe an attacker-controlled Azure app is their own, and lead them to connect the plugin to the attacker's account during configuration after upgrading to Pro.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Mar 18, 2026 · NIST NVD
Detected
The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the function in all versions up to, and including, 3.8.0. This is due to the function being hooked to without any check or nonce verification. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the site's Office 365 OAuth m
Jun 17, 2026 · NIST NVD
Updated
The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the function in all versions up to, and including, 3.8.0. This is due to the function being hooked to without any check or nonce verification. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the site's Office 365 OAuth m
Sources
- CVE.orgVulnerability recordCVE-2026-2559
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-2559
The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the function in all versions up to, and including, 3.8.0. This is due to the function being hooked to withou
nvd.nist.gov