CVE-2026-2559 - Changeset Plugin
CVE-2026-2559
The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `handle_office365_oauth_redirect()` function in all versions up to, and including, 3.8.0. This is due to the function being hooked to `admin_init` without any `current_user_can()` 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.
CVE-2026-2559
MEDIUM
CVSS 5.3
Published 2026-03-18
Updated 2026-03-19
AI Risk Moderate (54/100)
Active Exploit: No strong signal
Published Exploit: No public exploit references
Priority: P4 Planned
Severity Band
MEDIUM
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
Affected Components
3
Reference Links
4
AI Risk Engine
Moderate (54/100)
Exploitability
High
Active Exploitation
No strong signal
Published Exploit Status
No public exploit references
AI Context
Machine-generated threat intelligence
AI
Updated 7 days ago
AI enriched 7 days ago (2026-04-09 06:48 UTC)
Technical Summary
The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `handle_office365_oauth_redirect()` function in all versions up to, and including, 3.8.0. This is due to the function being hooked to `admin_init` without any `current_user_can()` 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.…
Potential Impact
Severity is MEDIUM (CVSS 5.3). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.
Exploitability Assessment
Exploitability is assessed as High based on remote code execution potential.
Primary risk drivers: remote code execution potential
Mitigation Recommendations
Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.
Detection & Monitoring
Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.
Business Impact Lens
Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.
